<?xml version="1.0" encoding="UTF-8"?>

<!--XBRL Document Created with Wdesk from Workiva-->
<!--Copyright 2023 Workiva-->
<!--r:ad8fc090-fb30-4fe5-8090-619fa178a327,g:f136dd25-e364-4a4a-8c83-2b3eb55e5c68-->
<link:linkbase xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xsi:schemaLocation="http://www.xbrl.org/2003/linkbase http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd">
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/all" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#all"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#hypercube-dimension"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-default"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#dimension-domain"/>
  <link:arcroleRef arcroleURI="http://xbrl.org/int/dim/arcrole/domain-member" xlink:type="simple" xlink:href="http://www.xbrl.org/2005/xbrldt-2005.xsd#domain-member"/>
  <link:roleRef roleURI="http://soterahealth.com/role/ConsolidatedStatementsofOperationsandComprehensiveIncome" xlink:type="simple" xlink:href="shc-20230331.xsd#ConsolidatedStatementsofOperationsandComprehensiveIncome"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/ConsolidatedStatementsofOperationsandComprehensiveIncome" xlink:type="extended" id="i41c908e35eef40baa1caa047fff59e97_ConsolidatedStatementsofOperationsandComprehensiveIncome">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_93929df2-b1a4-47da-a42e-1884e3c40a0e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenuesAbstract_d64b8bfe-3e67-4aa3-b756-df56d4a346c9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenuesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93929df2-b1a4-47da-a42e-1884e3c40a0e" xlink:to="loc_us-gaap_RevenuesAbstract_d64b8bfe-3e67-4aa3-b756-df56d4a346c9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_34870d3b-6fcd-4c3b-8c32-26428601d060" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RevenuesAbstract_d64b8bfe-3e67-4aa3-b756-df56d4a346c9" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_34870d3b-6fcd-4c3b-8c32-26428601d060" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfRevenueAbstract_9c54181b-9ace-47b1-b3b3-a2f25b76aa48" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CostOfRevenueAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93929df2-b1a4-47da-a42e-1884e3c40a0e" xlink:to="loc_us-gaap_CostOfRevenueAbstract_9c54181b-9ace-47b1-b3b3-a2f25b76aa48" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfRevenue_39711e92-eef9-49b8-86c4-62178b999381" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CostOfRevenue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CostOfRevenueAbstract_9c54181b-9ace-47b1-b3b3-a2f25b76aa48" xlink:to="loc_us-gaap_CostOfRevenue_39711e92-eef9-49b8-86c4-62178b999381" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GrossProfit_39d72d23-cc44-4399-8106-f707dabb63f9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GrossProfit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93929df2-b1a4-47da-a42e-1884e3c40a0e" xlink:to="loc_us-gaap_GrossProfit_39d72d23-cc44-4399-8106-f707dabb63f9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpensesAbstract_939e4a11-10bc-4842-84da-5af6c57a6b63" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingExpensesAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93929df2-b1a4-47da-a42e-1884e3c40a0e" xlink:to="loc_us-gaap_OperatingExpensesAbstract_939e4a11-10bc-4842-84da-5af6c57a6b63" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SellingGeneralAndAdministrativeExpense_692b72fe-93a2-4fe0-8566-37146990e0a2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SellingGeneralAndAdministrativeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_939e4a11-10bc-4842-84da-5af6c57a6b63" xlink:to="loc_us-gaap_SellingGeneralAndAdministrativeExpense_692b72fe-93a2-4fe0-8566-37146990e0a2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_AmortizationOfIntangibleAssetsNonproduction_5dbd14da-9355-4968-832a-b939f1ddf757" xlink:href="shc-20230331.xsd#shc_AmortizationOfIntangibleAssetsNonproduction"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_939e4a11-10bc-4842-84da-5af6c57a6b63" xlink:to="loc_shc_AmortizationOfIntangibleAssetsNonproduction_5dbd14da-9355-4968-832a-b939f1ddf757" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingExpenses_46cd80e1-59b1-4e87-98d6-bdb9587ca6e2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingExpenses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OperatingExpensesAbstract_939e4a11-10bc-4842-84da-5af6c57a6b63" xlink:to="loc_us-gaap_OperatingExpenses_46cd80e1-59b1-4e87-98d6-bdb9587ca6e2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingIncomeLoss_693cf77f-8cd6-4a22-b558-5010521e9337" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93929df2-b1a4-47da-a42e-1884e3c40a0e" xlink:to="loc_us-gaap_OperatingIncomeLoss_693cf77f-8cd6-4a22-b558-5010521e9337" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestIncomeExpenseNonoperatingNet_bfb66117-addb-4866-8191-73f2406e11c5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestIncomeExpenseNonoperatingNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93929df2-b1a4-47da-a42e-1884e3c40a0e" xlink:to="loc_us-gaap_InterestIncomeExpenseNonoperatingNet_bfb66117-addb-4866-8191-73f2406e11c5" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax_aca110fc-6c0e-4a86-a772-029954c44f2a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ForeignCurrencyTransactionGainLossBeforeTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93929df2-b1a4-47da-a42e-1884e3c40a0e" xlink:to="loc_us-gaap_ForeignCurrencyTransactionGainLossBeforeTax_aca110fc-6c0e-4a86-a772-029954c44f2a" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherNonoperatingIncomeExpense_d2907d43-52b5-49da-be7e-34688b903678" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherNonoperatingIncomeExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93929df2-b1a4-47da-a42e-1884e3c40a0e" xlink:to="loc_us-gaap_OtherNonoperatingIncomeExpense_d2907d43-52b5-49da-be7e-34688b903678" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_6a70b446-f2cf-4edc-98cd-a27f3110407d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93929df2-b1a4-47da-a42e-1884e3c40a0e" xlink:to="loc_us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesExtraordinaryItemsNoncontrollingInterest_6a70b446-f2cf-4edc-98cd-a27f3110407d" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeTaxExpenseBenefit_337ac4bb-3489-476e-a331-c8cd71755def" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeTaxExpenseBenefit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93929df2-b1a4-47da-a42e-1884e3c40a0e" xlink:to="loc_us-gaap_IncomeTaxExpenseBenefit_337ac4bb-3489-476e-a331-c8cd71755def" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_ceec2e53-75b2-44bf-9e84-c7bf5714b7c6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93929df2-b1a4-47da-a42e-1884e3c40a0e" xlink:to="loc_us-gaap_ProfitLoss_ceec2e53-75b2-44bf-9e84-c7bf5714b7c6" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract_55d1e42a-57e9-4742-80e8-cdde47c3453d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93929df2-b1a4-47da-a42e-1884e3c40a0e" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract_55d1e42a-57e9-4742-80e8-cdde47c3453d" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax_8467a177-a27c-4a60-91c7-1a8e2110dd8b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract_55d1e42a-57e9-4742-80e8-cdde47c3453d" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax_8467a177-a27c-4a60-91c7-1a8e2110dd8b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax_980dcefa-4251-476b-b2f0-09d4dc7ef2b8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract_55d1e42a-57e9-4742-80e8-cdde47c3453d" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax_980dcefa-4251-476b-b2f0-09d4dc7ef2b8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_f04a644d-1518-4ed8-bf4f-2f6b1c693b3a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTaxPortionAttributableToParentAbstract_55d1e42a-57e9-4742-80e8-cdde47c3453d" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossForeignCurrencyTransactionAndTranslationAdjustmentNetOfTax_f04a644d-1518-4ed8-bf4f-2f6b1c693b3a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_01844a5a-3760-4c18-b1dc-7b04ae07d3e7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93929df2-b1a4-47da-a42e-1884e3c40a0e" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_01844a5a-3760-4c18-b1dc-7b04ae07d3e7" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareAbstract_ad6be9e2-5582-4f1c-8a95-6a80927e55d8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EarningsPerShareAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93929df2-b1a4-47da-a42e-1884e3c40a0e" xlink:to="loc_us-gaap_EarningsPerShareAbstract_ad6be9e2-5582-4f1c-8a95-6a80927e55d8" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareBasic_bef4e02c-22c2-4253-b36f-8c55a6ea316d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EarningsPerShareBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_ad6be9e2-5582-4f1c-8a95-6a80927e55d8" xlink:to="loc_us-gaap_EarningsPerShareBasic_bef4e02c-22c2-4253-b36f-8c55a6ea316d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EarningsPerShareDiluted_41abb16c-92eb-4081-bd3d-d2250868d5ca" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EarningsPerShareDiluted"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EarningsPerShareAbstract_ad6be9e2-5582-4f1c-8a95-6a80927e55d8" xlink:to="loc_us-gaap_EarningsPerShareDiluted_41abb16c-92eb-4081-bd3d-d2250868d5ca" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustmentAbstract_334970f0-67a3-4c88-9a5a-09ef8128286a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustmentAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_93929df2-b1a4-47da-a42e-1884e3c40a0e" xlink:to="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustmentAbstract_334970f0-67a3-4c88-9a5a-09ef8128286a" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_2e035a69-0b32-4279-a52c-04e36bf6a64c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_WeightedAverageNumberOfSharesOutstandingBasic"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustmentAbstract_334970f0-67a3-4c88-9a5a-09ef8128286a" xlink:to="loc_us-gaap_WeightedAverageNumberOfSharesOutstandingBasic_2e035a69-0b32-4279-a52c-04e36bf6a64c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_b6417022-faf2-4c26-aafd-576a1705142b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_WeightedAverageNumberDilutedSharesOutstandingAdjustmentAbstract_334970f0-67a3-4c88-9a5a-09ef8128286a" xlink:to="loc_us-gaap_WeightedAverageNumberOfDilutedSharesOutstanding_b6417022-faf2-4c26-aafd-576a1705142b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_53a1a03e-2dc7-4bda-8cbd-a8f9cd127063" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_93929df2-b1a4-47da-a42e-1884e3c40a0e" xlink:to="loc_us-gaap_StatementTable_53a1a03e-2dc7-4bda-8cbd-a8f9cd127063" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductOrServiceAxis_2bf2d4c3-001d-4d06-9741-e4a64cff4f9d" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_53a1a03e-2dc7-4bda-8cbd-a8f9cd127063" xlink:to="loc_srt_ProductOrServiceAxis_2bf2d4c3-001d-4d06-9741-e4a64cff4f9d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_2bf2d4c3-001d-4d06-9741-e4a64cff4f9d_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ProductOrServiceAxis_2bf2d4c3-001d-4d06-9741-e4a64cff4f9d" xlink:to="loc_srt_ProductsAndServicesDomain_2bf2d4c3-001d-4d06-9741-e4a64cff4f9d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ProductsAndServicesDomain_cc709a77-4ec9-4f72-927d-efd8d1c53d2d" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ProductsAndServicesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ProductOrServiceAxis_2bf2d4c3-001d-4d06-9741-e4a64cff4f9d" xlink:to="loc_srt_ProductsAndServicesDomain_cc709a77-4ec9-4f72-927d-efd8d1c53d2d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ServiceMember_68eac885-d50e-41e6-9634-12135091cae2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ServiceMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_cc709a77-4ec9-4f72-927d-efd8d1c53d2d" xlink:to="loc_us-gaap_ServiceMember_68eac885-d50e-41e6-9634-12135091cae2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProductMember_df9908c3-f185-4551-81cb-2951f56d4c76" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProductMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ProductsAndServicesDomain_cc709a77-4ec9-4f72-927d-efd8d1c53d2d" xlink:to="loc_us-gaap_ProductMember_df9908c3-f185-4551-81cb-2951f56d4c76" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/ConsolidatedStatementsofEquity" xlink:type="simple" xlink:href="shc-20230331.xsd#ConsolidatedStatementsofEquity"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/ConsolidatedStatementsofEquity" xlink:type="extended" id="i3828ce2b20f845f69cf4a4f4df4435e6_ConsolidatedStatementsofEquity">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementLineItems_f8fc2b26-6af6-4616-ab2e-3095233917c7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_cd343883-45e3-4302-8572-7d38df269245" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncreaseDecreaseInStockholdersEquityRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_StatementLineItems_f8fc2b26-6af6-4616-ab2e-3095233917c7" xlink:to="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_cd343883-45e3-4302-8572-7d38df269245" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_b23de698-36ea-4d67-aa3e-ee0b27fb8662" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_cd343883-45e3-4302-8572-7d38df269245" xlink:to="loc_us-gaap_CommonStockSharesOutstanding_b23de698-36ea-4d67-aa3e-ee0b27fb8662" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_471d9e89-e18f-456f-a34a-c11dc1b7d44f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_cd343883-45e3-4302-8572-7d38df269245" xlink:to="loc_us-gaap_StockholdersEquity_471d9e89-e18f-456f-a34a-c11dc1b7d44f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_612445f9-5abe-4e44-978a-0fd9f217a482" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_cd343883-45e3-4302-8572-7d38df269245" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_612445f9-5abe-4e44-978a-0fd9f217a482" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_8107670a-fa19-451e-8754-2cbe1cd98d0a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_cd343883-45e3-4302-8572-7d38df269245" xlink:to="loc_us-gaap_StockIssuedDuringPeriodValueShareBasedCompensation_8107670a-fa19-451e-8754-2cbe1cd98d0a" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterestAbstract_89bdad91-0aba-43b4-a8db-15b335b2b975" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterestAbstract"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncreaseDecreaseInStockholdersEquityRollForward_cd343883-45e3-4302-8572-7d38df269245" xlink:to="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterestAbstract_89bdad91-0aba-43b4-a8db-15b335b2b975" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax_a98818fd-fc75-4d51-b018-3747cdf232ec" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterestAbstract_89bdad91-0aba-43b4-a8db-15b335b2b975" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossPensionAndOtherPostretirementBenefitPlansAdjustmentNetOfTax_a98818fd-fc75-4d51-b018-3747cdf232ec" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent_0a053544-e0d9-4fe0-bd9b-7a032ca59ffd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterestAbstract_89bdad91-0aba-43b4-a8db-15b335b2b975" xlink:to="loc_us-gaap_OtherComprehensiveIncomeForeignCurrencyTransactionAndTranslationAdjustmentNetOfTaxPortionAttributableToParent_0a053544-e0d9-4fe0-bd9b-7a032ca59ffd" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax_fef18f19-96c0-4efc-952e-8e13bedef673" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterestAbstract_89bdad91-0aba-43b4-a8db-15b335b2b975" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax_fef18f19-96c0-4efc-952e-8e13bedef673" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ProfitLoss_822ed8c3-e8ff-493c-8721-60e2b2c1841b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ProfitLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterestAbstract_89bdad91-0aba-43b4-a8db-15b335b2b975" xlink:to="loc_us-gaap_ProfitLoss_822ed8c3-e8ff-493c-8721-60e2b2c1841b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockSharesOutstanding_35a03830-85c6-4b45-a563-7d4036f0a5c6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockSharesOutstanding"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_01c78643-b8de-48aa-a08e-bb319743bd77" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementTable_5e295ce5-1581-4de4-8570-fac6516761b9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_StatementLineItems_f8fc2b26-6af6-4616-ab2e-3095233917c7" xlink:to="loc_us-gaap_StatementTable_5e295ce5-1581-4de4-8570-fac6516761b9" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_6ca7670f-61a2-489b-9292-ea627f9dfe7d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_StatementTable_5e295ce5-1581-4de4-8570-fac6516761b9" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_6ca7670f-61a2-489b-9292-ea627f9dfe7d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_6ca7670f-61a2-489b-9292-ea627f9dfe7d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_6ca7670f-61a2-489b-9292-ea627f9dfe7d" xlink:to="loc_us-gaap_EquityComponentDomain_6ca7670f-61a2-489b-9292-ea627f9dfe7d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_4c98e988-cfc8-4c94-875f-9adc39d0e91c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_6ca7670f-61a2-489b-9292-ea627f9dfe7d" xlink:to="loc_us-gaap_EquityComponentDomain_4c98e988-cfc8-4c94-875f-9adc39d0e91c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CommonStockMember_0127936d-0338-4969-b66f-5793576343de" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CommonStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_4c98e988-cfc8-4c94-875f-9adc39d0e91c" xlink:to="loc_us-gaap_CommonStockMember_0127936d-0338-4969-b66f-5793576343de" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TreasuryStockCommonMember_821513f7-f835-458e-bc0e-a746113435c3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TreasuryStockCommonMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_4c98e988-cfc8-4c94-875f-9adc39d0e91c" xlink:to="loc_us-gaap_TreasuryStockCommonMember_821513f7-f835-458e-bc0e-a746113435c3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AdditionalPaidInCapitalMember_78f30f37-95ef-4d61-83fe-95397a929619" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AdditionalPaidInCapitalMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_4c98e988-cfc8-4c94-875f-9adc39d0e91c" xlink:to="loc_us-gaap_AdditionalPaidInCapitalMember_78f30f37-95ef-4d61-83fe-95397a929619" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetainedEarningsMember_e363926b-b260-42eb-b7ed-91f1646a2ca1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetainedEarningsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_4c98e988-cfc8-4c94-875f-9adc39d0e91c" xlink:to="loc_us-gaap_RetainedEarningsMember_e363926b-b260-42eb-b7ed-91f1646a2ca1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_1746b8e8-d9d8-4bcd-9376-8594fc9a6c92" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_4c98e988-cfc8-4c94-875f-9adc39d0e91c" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_1746b8e8-d9d8-4bcd-9376-8594fc9a6c92" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/BasisofPresentationDetails" xlink:type="simple" xlink:href="shc-20230331.xsd#BasisofPresentationDetails"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/BasisofPresentationDetails" xlink:type="extended" id="i9523caa5df854205a8c956af7349b2bf_BasisofPresentationDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestEffectsOfChangesNetLineItems_7be324fe-2e59-41f9-9d41-0943bf6531ac" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestEffectsOfChangesNetLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_fc3428e8-5758-4dd5-83c8-ae7023ca6b1e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestEffectsOfChangesNetLineItems_7be324fe-2e59-41f9-9d41-0943bf6531ac" xlink:to="loc_us-gaap_EquityMethodInvestmentOwnershipPercentage_fc3428e8-5758-4dd5-83c8-ae7023ca6b1e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InvestmentsFairValueDisclosure_da29f0be-cb4a-4333-bb07-f7a664081204" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InvestmentsFairValueDisclosure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestEffectsOfChangesNetLineItems_7be324fe-2e59-41f9-9d41-0943bf6531ac" xlink:to="loc_us-gaap_InvestmentsFairValueDisclosure_da29f0be-cb4a-4333-bb07-f7a664081204" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment_8e1ee3e6-0485-40f9-a709-349203d2bb0b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestEffectsOfChangesNetLineItems_7be324fe-2e59-41f9-9d41-0943bf6531ac" xlink:to="loc_us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment_8e1ee3e6-0485-40f9-a709-349203d2bb0b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestEffectsOfChangesNetTable_9d6c69a9-c05c-4cc1-9b41-b7821f523ac7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestEffectsOfChangesNetTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestEffectsOfChangesNetLineItems_7be324fe-2e59-41f9-9d41-0943bf6531ac" xlink:to="loc_us-gaap_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestEffectsOfChangesNetTable_9d6c69a9-c05c-4cc1-9b41-b7821f523ac7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_d104e1b7-90f0-4107-9579-9cbdec153b95" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestEffectsOfChangesNetTable_9d6c69a9-c05c-4cc1-9b41-b7821f523ac7" xlink:to="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_d104e1b7-90f0-4107-9579-9cbdec153b95" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_d104e1b7-90f0-4107-9579-9cbdec153b95_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_d104e1b7-90f0-4107-9579-9cbdec153b95" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_d104e1b7-90f0-4107-9579-9cbdec153b95_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_EquityMethodInvesteeNameDomain_ba95eeec-2282-499e-a67c-faaab02b7a53" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_EquityMethodInvesteeNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis_d104e1b7-90f0-4107-9579-9cbdec153b95" xlink:to="loc_srt_EquityMethodInvesteeNameDomain_ba95eeec-2282-499e-a67c-faaab02b7a53" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_UnnamedEBeamJointVentureMember_872e8c72-d1d5-41e6-b2e6-ccc1d8c021fe" xlink:href="shc-20230331.xsd#shc_UnnamedEBeamJointVentureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_ba95eeec-2282-499e-a67c-faaab02b7a53" xlink:to="loc_shc_UnnamedEBeamJointVentureMember_872e8c72-d1d5-41e6-b2e6-ccc1d8c021fe" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_AuraluxMember_514cdbca-f389-4757-8dc4-ae306a96a15c" xlink:href="shc-20230331.xsd#shc_AuraluxMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_EquityMethodInvesteeNameDomain_ba95eeec-2282-499e-a67c-faaab02b7a53" xlink:to="loc_shc_AuraluxMember_514cdbca-f389-4757-8dc4-ae306a96a15c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_28df6dd5-add6-438d-b9c2-9ac18aca4a1a" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ConsolidationLessThanWhollyOwnedSubsidiaryParentOwnershipInterestEffectsOfChangesNetTable_9d6c69a9-c05c-4cc1-9b41-b7821f523ac7" xlink:to="loc_dei_LegalEntityAxis_28df6dd5-add6-438d-b9c2-9ac18aca4a1a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_28df6dd5-add6-438d-b9c2-9ac18aca4a1a_default" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_28df6dd5-add6-438d-b9c2-9ac18aca4a1a" xlink:to="loc_dei_EntityDomain_28df6dd5-add6-438d-b9c2-9ac18aca4a1a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_98af19ad-5aaf-4e4b-9b02-ddfc5dfc66ca" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_28df6dd5-add6-438d-b9c2-9ac18aca4a1a" xlink:to="loc_dei_EntityDomain_98af19ad-5aaf-4e4b-9b02-ddfc5dfc66ca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_IotronIndustriesCanadaIncIotronMember_6c785271-cb69-4a9f-a427-c34cd8dc6604" xlink:href="shc-20230331.xsd#shc_IotronIndustriesCanadaIncIotronMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_98af19ad-5aaf-4e4b-9b02-ddfc5dfc66ca" xlink:to="loc_shc_IotronIndustriesCanadaIncIotronMember_6c785271-cb69-4a9f-a427-c34cd8dc6604" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/RevenueRecognitionDetails" xlink:type="simple" xlink:href="shc-20230331.xsd#RevenueRecognitionDetails"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/RevenueRecognitionDetails" xlink:type="extended" id="i7c601c4645c44645869240031627f990_RevenueRecognitionDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueLineItems_7fbc65b2-5287-4ff3-ac70-573e6495839d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DisaggregationOfRevenueLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_400d8b78-ec91-4479-8dbf-78103faf66ae" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_7fbc65b2-5287-4ff3-ac70-573e6495839d" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_400d8b78-ec91-4479-8dbf-78103faf66ae" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DisaggregationOfRevenueTable_db601dd0-e286-486b-9871-439aeec2a522" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DisaggregationOfRevenueTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DisaggregationOfRevenueLineItems_7fbc65b2-5287-4ff3-ac70-573e6495839d" xlink:to="loc_us-gaap_DisaggregationOfRevenueTable_db601dd0-e286-486b-9871-439aeec2a522" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_a23eb98a-c017-46fb-84bd-447651fa4417" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_db601dd0-e286-486b-9871-439aeec2a522" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_a23eb98a-c017-46fb-84bd-447651fa4417" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_a23eb98a-c017-46fb-84bd-447651fa4417_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_a23eb98a-c017-46fb-84bd-447651fa4417" xlink:to="loc_us-gaap_SegmentDomain_a23eb98a-c017-46fb-84bd-447651fa4417_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_ef695278-2f64-4930-900f-34e73eb003f3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_a23eb98a-c017-46fb-84bd-447651fa4417" xlink:to="loc_us-gaap_SegmentDomain_ef695278-2f64-4930-900f-34e73eb003f3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_SterigenicsMember_536dd3c5-6daa-4eaf-8aab-21a348060b02" xlink:href="shc-20230331.xsd#shc_SterigenicsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_ef695278-2f64-4930-900f-34e73eb003f3" xlink:to="loc_shc_SterigenicsMember_536dd3c5-6daa-4eaf-8aab-21a348060b02" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_NordionMember_b059194a-6267-4b9d-951f-98db1900e63e" xlink:href="shc-20230331.xsd#shc_NordionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_ef695278-2f64-4930-900f-34e73eb003f3" xlink:to="loc_shc_NordionMember_b059194a-6267-4b9d-951f-98db1900e63e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_NelsonLabsMember_878dff62-460e-4ce7-9e08-a7e3f2cf49a4" xlink:href="shc-20230331.xsd#shc_NelsonLabsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_ef695278-2f64-4930-900f-34e73eb003f3" xlink:to="loc_shc_NelsonLabsMember_878dff62-460e-4ce7-9e08-a7e3f2cf49a4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_4f170a11-43f1-4a3e-9511-8607aae0ceee" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TimingOfTransferOfGoodOrServiceAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DisaggregationOfRevenueTable_db601dd0-e286-486b-9871-439aeec2a522" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_4f170a11-43f1-4a3e-9511-8607aae0ceee" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_4f170a11-43f1-4a3e-9511-8607aae0ceee_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TimingOfTransferOfGoodOrServiceDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_4f170a11-43f1-4a3e-9511-8607aae0ceee" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_4f170a11-43f1-4a3e-9511-8607aae0ceee_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_bdedc99d-339d-4437-9364-cf9f6bf64f0b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TimingOfTransferOfGoodOrServiceDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceAxis_4f170a11-43f1-4a3e-9511-8607aae0ceee" xlink:to="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_bdedc99d-339d-4437-9364-cf9f6bf64f0b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransferredAtPointInTimeMember_edfd7371-62d7-4885-ba54-ae5313f24d7f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TransferredAtPointInTimeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_bdedc99d-339d-4437-9364-cf9f6bf64f0b" xlink:to="loc_us-gaap_TransferredAtPointInTimeMember_edfd7371-62d7-4885-ba54-ae5313f24d7f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TransferredOverTimeMember_678436a5-c7a4-450d-8f36-d25374d5f92b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TransferredOverTimeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_TimingOfTransferOfGoodOrServiceDomain_bdedc99d-339d-4437-9364-cf9f6bf64f0b" xlink:to="loc_us-gaap_TransferredOverTimeMember_678436a5-c7a4-450d-8f36-d25374d5f92b" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/AcquisitionsDetails" xlink:type="simple" xlink:href="shc-20230331.xsd#AcquisitionsDetails"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/AcquisitionsDetails" xlink:type="extended" id="ic898af397bf54dad8da7f0b544a4433d_AcquisitionsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionLineItems_75042d3b-4926-4220-b8af-beaa09c90dcc" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationConsiderationTransferred1_dad571aa-fb61-4a30-980d-f2346216b251" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationConsiderationTransferred1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_75042d3b-4926-4220-b8af-beaa09c90dcc" xlink:to="loc_us-gaap_BusinessCombinationConsiderationTransferred1_dad571aa-fb61-4a30-980d-f2346216b251" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CashAcquiredFromAcquisition_cc0789ac-57c5-4512-b2ce-0cd227bb9b3d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CashAcquiredFromAcquisition"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_75042d3b-4926-4220-b8af-beaa09c90dcc" xlink:to="loc_us-gaap_CashAcquiredFromAcquisition_cc0789ac-57c5-4512-b2ce-0cd227bb9b3d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_354b6d12-e422-436b-84dc-cefbdde9b347" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_75042d3b-4926-4220-b8af-beaa09c90dcc" xlink:to="loc_us-gaap_Goodwill_354b6d12-e422-436b-84dc-cefbdde9b347" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_23f2e5b3-c143-45eb-bece-66f3aa38271f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_75042d3b-4926-4220-b8af-beaa09c90dcc" xlink:to="loc_us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedIntangibles_23f2e5b3-c143-45eb-bece-66f3aa38271f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_cc6a6eb8-4875-4d65-b246-78e13ecc2325" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_BusinessAcquisitionLineItems_75042d3b-4926-4220-b8af-beaa09c90dcc" xlink:to="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_cc6a6eb8-4875-4d65-b246-78e13ecc2325" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAxis_d6587673-bde8-4f08-a86d-73028ada56c2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_cc6a6eb8-4875-4d65-b246-78e13ecc2325" xlink:to="loc_us-gaap_BusinessAcquisitionAxis_d6587673-bde8-4f08-a86d-73028ada56c2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_d6587673-bde8-4f08-a86d-73028ada56c2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_d6587673-bde8-4f08-a86d-73028ada56c2" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_d6587673-bde8-4f08-a86d-73028ada56c2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessAcquisitionAcquireeDomain_0ef1fb74-1182-484a-8a8a-3e578643e139" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessAcquisitionAcquireeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_BusinessAcquisitionAxis_d6587673-bde8-4f08-a86d-73028ada56c2" xlink:to="loc_us-gaap_BusinessAcquisitionAcquireeDomain_0ef1fb74-1182-484a-8a8a-3e578643e139" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_RegulatoryComplianceAssociatesIncRCAMember_90b2a88f-80b0-40f2-aca6-49566611b00e" xlink:href="shc-20230331.xsd#shc_RegulatoryComplianceAssociatesIncRCAMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_BusinessAcquisitionAcquireeDomain_0ef1fb74-1182-484a-8a8a-3e578643e139" xlink:to="loc_shc_RegulatoryComplianceAssociatesIncRCAMember_90b2a88f-80b0-40f2-aca6-49566611b00e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_158124ae-9ebe-4d55-822c-769b2106d9c6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfBusinessAcquisitionsByAcquisitionTable_cc6a6eb8-4875-4d65-b246-78e13ecc2325" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_158124ae-9ebe-4d55-822c-769b2106d9c6" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_158124ae-9ebe-4d55-822c-769b2106d9c6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_158124ae-9ebe-4d55-822c-769b2106d9c6" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_158124ae-9ebe-4d55-822c-769b2106d9c6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_b3b99072-264b-4bcc-9cab-ccd96ce51855" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_158124ae-9ebe-4d55-822c-769b2106d9c6" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_b3b99072-264b-4bcc-9cab-ccd96ce51855" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_ac0b4a52-d708-4214-b7c4-66426cdf113c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_b3b99072-264b-4bcc-9cab-ccd96ce51855" xlink:to="loc_us-gaap_CustomerRelationshipsMember_ac0b4a52-d708-4214-b7c4-66426cdf113c" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/GoodwillandOtherIntangibleAssetsScheduleofGoodwillDetails" xlink:type="simple" xlink:href="shc-20230331.xsd#GoodwillandOtherIntangibleAssetsScheduleofGoodwillDetails"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/GoodwillandOtherIntangibleAssetsScheduleofGoodwillDetails" xlink:type="extended" id="if5512cda853a4a879ab9ba91beb1348c_GoodwillandOtherIntangibleAssetsScheduleofGoodwillDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillLineItems_1ca1937f-89be-4eb5-aa0d-a19cbd458534" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GoodwillLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillRollForward_64be02ff-beb3-4dfd-aaba-a4b728d289dc" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GoodwillRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillLineItems_1ca1937f-89be-4eb5-aa0d-a19cbd458534" xlink:to="loc_us-gaap_GoodwillRollForward_64be02ff-beb3-4dfd-aaba-a4b728d289dc" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_06ad6775-9f35-4ae1-802e-0c35f81a0809" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_Goodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_64be02ff-beb3-4dfd-aaba-a4b728d289dc" xlink:to="loc_us-gaap_Goodwill_06ad6775-9f35-4ae1-802e-0c35f81a0809" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_20f63ba9-3d04-4638-89dc-116fb50b8f3f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GoodwillForeignCurrencyTranslationGainLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GoodwillRollForward_64be02ff-beb3-4dfd-aaba-a4b728d289dc" xlink:to="loc_us-gaap_GoodwillForeignCurrencyTranslationGainLoss_20f63ba9-3d04-4638-89dc-116fb50b8f3f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_Goodwill_04a6a709-7c7a-4813-aba2-13378b8b0ad3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_Goodwill"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfGoodwillTable_85439f09-9a1b-46c0-b5c9-87c90122ecdd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfGoodwillTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GoodwillLineItems_1ca1937f-89be-4eb5-aa0d-a19cbd458534" xlink:to="loc_us-gaap_ScheduleOfGoodwillTable_85439f09-9a1b-46c0-b5c9-87c90122ecdd" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_456ab81b-cd5f-4595-b321-40cbfc0ccc9d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfGoodwillTable_85439f09-9a1b-46c0-b5c9-87c90122ecdd" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_456ab81b-cd5f-4595-b321-40cbfc0ccc9d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_456ab81b-cd5f-4595-b321-40cbfc0ccc9d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_456ab81b-cd5f-4595-b321-40cbfc0ccc9d" xlink:to="loc_us-gaap_SegmentDomain_456ab81b-cd5f-4595-b321-40cbfc0ccc9d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_44ba4383-adc2-4ab3-a95a-7731c84078f3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_456ab81b-cd5f-4595-b321-40cbfc0ccc9d" xlink:to="loc_us-gaap_SegmentDomain_44ba4383-adc2-4ab3-a95a-7731c84078f3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_SterigenicsMember_14e4ee5f-eadc-46f9-b403-b39583e85ad7" xlink:href="shc-20230331.xsd#shc_SterigenicsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_44ba4383-adc2-4ab3-a95a-7731c84078f3" xlink:to="loc_shc_SterigenicsMember_14e4ee5f-eadc-46f9-b403-b39583e85ad7" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_NordionMember_ea91f8d1-f885-4483-a461-7a0ab4616120" xlink:href="shc-20230331.xsd#shc_NordionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_44ba4383-adc2-4ab3-a95a-7731c84078f3" xlink:to="loc_shc_NordionMember_ea91f8d1-f885-4483-a461-7a0ab4616120" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_NelsonLabsMember_cec15458-5eee-4e56-92f0-15dbd1482842" xlink:href="shc-20230331.xsd#shc_NelsonLabsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_44ba4383-adc2-4ab3-a95a-7731c84078f3" xlink:to="loc_shc_NelsonLabsMember_cec15458-5eee-4e56-92f0-15dbd1482842" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/GoodwillandOtherIntangibleAssetsScheduleofIntangibleAssetsDetails" xlink:type="simple" xlink:href="shc-20230331.xsd#GoodwillandOtherIntangibleAssetsScheduleofIntangibleAssetsDetails"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/GoodwillandOtherIntangibleAssetsScheduleofIntangibleAssetsDetails" xlink:type="extended" id="i7bd2752bd9624a6aa8f2c61ef21ea294_GoodwillandOtherIntangibleAssetsScheduleofIntangibleAssetsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_e2e3061e-e327-470d-baf8-e2bf229ebfb8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsGross_16c7efbe-94cd-44bc-a7b7-4f72e8022f79" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_e2e3061e-e327-470d-baf8-e2bf229ebfb8" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsGross_16c7efbe-94cd-44bc-a7b7-4f72e8022f79" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_5a984baa-5f37-4fac-b5a9-d4223c44b3a7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_e2e3061e-e327-470d-baf8-e2bf229ebfb8" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsAccumulatedAmortization_5a984baa-5f37-4fac-b5a9-d4223c44b3a7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_4475d5c9-198e-4a7d-abf6-2e5e118ec90e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AcquiredFiniteLivedIntangibleAssetsLineItems_e2e3061e-e327-470d-baf8-e2bf229ebfb8" xlink:to="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_4475d5c9-198e-4a7d-abf6-2e5e118ec90e" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_f94fedea-a707-4ee9-891c-d53d97efb53e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAcquiredFiniteLivedIntangibleAssetByMajorClassTable_4475d5c9-198e-4a7d-abf6-2e5e118ec90e" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_f94fedea-a707-4ee9-891c-d53d97efb53e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_f94fedea-a707-4ee9-891c-d53d97efb53e_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_f94fedea-a707-4ee9-891c-d53d97efb53e" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_f94fedea-a707-4ee9-891c-d53d97efb53e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_619c5ca9-c9f1-4639-8471-ce968af50efe" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_f94fedea-a707-4ee9-891c-d53d97efb53e" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_619c5ca9-c9f1-4639-8471-ce968af50efe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerRelationshipsMember_ba114694-c9c6-471d-aecd-82dd3ba20d99" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CustomerRelationshipsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_619c5ca9-c9f1-4639-8471-ce968af50efe" xlink:to="loc_us-gaap_CustomerRelationshipsMember_ba114694-c9c6-471d-aecd-82dd3ba20d99" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DevelopedTechnologyRightsMember_159de4d5-20e9-46dd-a1f1-92cc1400fcad" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DevelopedTechnologyRightsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_619c5ca9-c9f1-4639-8471-ce968af50efe" xlink:to="loc_us-gaap_DevelopedTechnologyRightsMember_159de4d5-20e9-46dd-a1f1-92cc1400fcad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TradeNamesMember_8755da4a-b363-4be9-b90a-7d8d7cd0c647" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_619c5ca9-c9f1-4639-8471-ce968af50efe" xlink:to="loc_us-gaap_TradeNamesMember_8755da4a-b363-4be9-b90a-7d8d7cd0c647" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_LandUseRightsMember_77f3966a-aad8-4ce3-a045-6b2e4ce76536" xlink:href="shc-20230331.xsd#shc_LandUseRightsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_619c5ca9-c9f1-4639-8471-ce968af50efe" xlink:to="loc_shc_LandUseRightsMember_77f3966a-aad8-4ce3-a045-6b2e4ce76536" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_SealedSourceAndSupplyAgreementsMember_bb8824d9-e3fb-4147-bd68-201e0d735b62" xlink:href="shc-20230331.xsd#shc_SealedSourceAndSupplyAgreementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_619c5ca9-c9f1-4639-8471-ce968af50efe" xlink:to="loc_shc_SealedSourceAndSupplyAgreementsMember_bb8824d9-e3fb-4147-bd68-201e0d735b62" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherIntangibleAssetsMember_de1eb79b-28ce-455b-9d1f-fe1619698bd7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherIntangibleAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_619c5ca9-c9f1-4639-8471-ce968af50efe" xlink:to="loc_us-gaap_OtherIntangibleAssetsMember_de1eb79b-28ce-455b-9d1f-fe1619698bd7" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AcquiredIndefiniteLivedIntangibleAssetsLineItems_5952d225-c9d0-4778-b34e-8ddd905db6ec" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AcquiredIndefiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_a5904ea5-a857-4fe4-b759-05229331f242" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredIndefiniteLivedIntangibleAssetsLineItems_5952d225-c9d0-4778-b34e-8ddd905db6ec" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsExcludingGoodwill_a5904ea5-a857-4fe4-b759-05229331f242" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_LicensingAgreementsRenewalTerm_d3f78f47-542f-4a35-8831-cb12b211b436" xlink:href="shc-20230331.xsd#shc_LicensingAgreementsRenewalTerm"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AcquiredIndefiniteLivedIntangibleAssetsLineItems_5952d225-c9d0-4778-b34e-8ddd905db6ec" xlink:to="loc_shc_LicensingAgreementsRenewalTerm_d3f78f47-542f-4a35-8831-cb12b211b436" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfAcquiredIndefiniteLivedIntangibleAssetsByMajorClassTable_d726548f-73d6-4bfa-b9c0-fbb035c8468f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfAcquiredIndefiniteLivedIntangibleAssetsByMajorClassTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AcquiredIndefiniteLivedIntangibleAssetsLineItems_5952d225-c9d0-4778-b34e-8ddd905db6ec" xlink:to="loc_us-gaap_ScheduleOfAcquiredIndefiniteLivedIntangibleAssetsByMajorClassTable_d726548f-73d6-4bfa-b9c0-fbb035c8468f" xlink:type="arc" order="2" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_35cea238-6183-4b1c-b00b-3007b21f551f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfAcquiredIndefiniteLivedIntangibleAssetsByMajorClassTable_d726548f-73d6-4bfa-b9c0-fbb035c8468f" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_35cea238-6183-4b1c-b00b-3007b21f551f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_35cea238-6183-4b1c-b00b-3007b21f551f_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_35cea238-6183-4b1c-b00b-3007b21f551f" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_35cea238-6183-4b1c-b00b-3007b21f551f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_4568a610-07db-4852-be99-86704c85ad33" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsByMajorClassAxis_35cea238-6183-4b1c-b00b-3007b21f551f" xlink:to="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_4568a610-07db-4852-be99-86704c85ad33" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LicensingAgreementsMember_70b6a4ba-b9ac-464a-9a57-3206f45e2b3c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LicensingAgreementsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_4568a610-07db-4852-be99-86704c85ad33" xlink:to="loc_us-gaap_LicensingAgreementsMember_70b6a4ba-b9ac-464a-9a57-3206f45e2b3c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_TrademarksAndTradeNamesMember_6e996609-7437-484c-99c9-37dc37694b1d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_TrademarksAndTradeNamesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IndefiniteLivedIntangibleAssetsMajorClassNameDomain_4568a610-07db-4852-be99-86704c85ad33" xlink:to="loc_us-gaap_TrademarksAndTradeNamesMember_6e996609-7437-484c-99c9-37dc37694b1d" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/GoodwillandOtherIntangibleAssetsNarrativeDetails" xlink:type="simple" xlink:href="shc-20230331.xsd#GoodwillandOtherIntangibleAssetsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/GoodwillandOtherIntangibleAssetsNarrativeDetails" xlink:type="extended" id="i9871bbdf73734cd5aac3ea4f51e9b430_GoodwillandOtherIntangibleAssetsNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_af7842e2-8d6a-451f-b566-00da900405d8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AmortizationOfIntangibleAssets_c0f286e2-5921-47f7-be1e-a7fbc5153d5c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AmortizationOfIntangibleAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_af7842e2-8d6a-451f-b566-00da900405d8" xlink:to="loc_us-gaap_AmortizationOfIntangibleAssets_c0f286e2-5921-47f7-be1e-a7fbc5153d5c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1_cce13c1c-5989-4e22-a793-2138a6c72da9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_af7842e2-8d6a-451f-b566-00da900405d8" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsRemainingAmortizationPeriod1_cce13c1c-5989-4e22-a793-2138a6c72da9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_a59d442b-0718-4348-9d7e-7737b6d02fdf" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsLineItems_af7842e2-8d6a-451f-b566-00da900405d8" xlink:to="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_a59d442b-0718-4348-9d7e-7737b6d02fdf" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_b9039684-5858-4a90-9827-e0dd1013875d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_a59d442b-0718-4348-9d7e-7737b6d02fdf" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_b9039684-5858-4a90-9827-e0dd1013875d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_b9039684-5858-4a90-9827-e0dd1013875d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_b9039684-5858-4a90-9827-e0dd1013875d" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_b9039684-5858-4a90-9827-e0dd1013875d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_09db709a-b0ba-4f48-acbc-8220cd21f869" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsByMajorClassAxis_b9039684-5858-4a90-9827-e0dd1013875d" xlink:to="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_09db709a-b0ba-4f48-acbc-8220cd21f869" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherIntangibleAssetsMember_5fb5af48-4395-42b7-93c6-f6c1e20e0d41" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherIntangibleAssetsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FiniteLivedIntangibleAssetsMajorClassNameDomain_09db709a-b0ba-4f48-acbc-8220cd21f869" xlink:to="loc_us-gaap_OtherIntangibleAssetsMember_5fb5af48-4395-42b7-93c6-f6c1e20e0d41" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationAxis_5c1126a9-ee7c-40e1-bca5-4d154b73a870" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfFiniteLivedIntangibleAssetsTable_a59d442b-0718-4348-9d7e-7737b6d02fdf" xlink:to="loc_us-gaap_IncomeStatementLocationAxis_5c1126a9-ee7c-40e1-bca5-4d154b73a870" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_5c1126a9-ee7c-40e1-bca5-4d154b73a870_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_5c1126a9-ee7c-40e1-bca5-4d154b73a870" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_5c1126a9-ee7c-40e1-bca5-4d154b73a870_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IncomeStatementLocationDomain_0e31346c-cf24-4b5b-a669-e1722e20d33f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IncomeStatementLocationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_IncomeStatementLocationAxis_5c1126a9-ee7c-40e1-bca5-4d154b73a870" xlink:to="loc_us-gaap_IncomeStatementLocationDomain_0e31346c-cf24-4b5b-a669-e1722e20d33f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CostOfSalesMember_21a6142c-bbc2-4d4f-84b4-4e0862d2f5a9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CostOfSalesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_0e31346c-cf24-4b5b-a669-e1722e20d33f" xlink:to="loc_us-gaap_CostOfSalesMember_21a6142c-bbc2-4d4f-84b4-4e0862d2f5a9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_AmortizationOfIntangibleAssetsNonProductionMember_a7d595c2-e837-4452-adcc-a050398d24aa" xlink:href="shc-20230331.xsd#shc_AmortizationOfIntangibleAssetsNonProductionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_IncomeStatementLocationDomain_0e31346c-cf24-4b5b-a669-e1722e20d33f" xlink:to="loc_shc_AmortizationOfIntangibleAssetsNonProductionMember_a7d595c2-e837-4452-adcc-a050398d24aa" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/LongTermDebtScheduleofLongtermDebtInstrumentsDetails" xlink:type="simple" xlink:href="shc-20230331.xsd#LongTermDebtScheduleofLongtermDebtInstrumentsDetails"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/LongTermDebtScheduleofLongtermDebtInstrumentsDetails" xlink:type="extended" id="idb3da4d7ffff483d861d9f713e01181f_LongTermDebtScheduleofLongtermDebtInstrumentsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_db4b0d8b-63ce-4407-b387-d08e240fd514" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_652403ab-dd0d-4b25-b675-f8c774bd8a73" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_db4b0d8b-63ce-4407-b387-d08e240fd514" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_652403ab-dd0d-4b25-b675-f8c774bd8a73" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_LongTermDebtCurrentMaturitiesGross_de487f1e-f149-44aa-b346-a89ec29cc964" xlink:href="shc-20230331.xsd#shc_LongTermDebtCurrentMaturitiesGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_db4b0d8b-63ce-4407-b387-d08e240fd514" xlink:to="loc_shc_LongTermDebtCurrentMaturitiesGross_de487f1e-f149-44aa-b346-a89ec29cc964" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_LongTermDebtGrossNoncurrent_48ae102b-76c1-49f6-ac31-38adf2766fcf" xlink:href="shc-20230331.xsd#shc_LongTermDebtGrossNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_db4b0d8b-63ce-4407-b387-d08e240fd514" xlink:to="loc_shc_LongTermDebtGrossNoncurrent_48ae102b-76c1-49f6-ac31-38adf2766fcf" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNet_61f38af7-b830-4ce6-8015-1e45f0c5a196" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredFinanceCostsNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_db4b0d8b-63ce-4407-b387-d08e240fd514" xlink:to="loc_us-gaap_DeferredFinanceCostsNet_61f38af7-b830-4ce6-8015-1e45f0c5a196" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsCurrentNet_864921b3-d413-4ffd-b66e-c530bb4e434e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredFinanceCostsCurrentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_db4b0d8b-63ce-4407-b387-d08e240fd514" xlink:to="loc_us-gaap_DeferredFinanceCostsCurrentNet_864921b3-d413-4ffd-b66e-c530bb4e434e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DeferredFinanceCostsNoncurrentNet_cce7107a-8ef6-4641-8789-689e056a6494" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DeferredFinanceCostsNoncurrentNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_db4b0d8b-63ce-4407-b387-d08e240fd514" xlink:to="loc_us-gaap_DeferredFinanceCostsNoncurrentNet_cce7107a-8ef6-4641-8789-689e056a6494" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscount_df43d8c0-2a1a-4c9a-a090-8838316ea701" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentUnamortizedDiscount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_db4b0d8b-63ce-4407-b387-d08e240fd514" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscount_df43d8c0-2a1a-4c9a-a090-8838316ea701" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_DebtInstrumentUnamortizedDiscountExcludingCurrentPortion_48b28ef9-ef25-4dad-b40d-44208aadf2d5" xlink:href="shc-20230331.xsd#shc_DebtInstrumentUnamortizedDiscountExcludingCurrentPortion"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_db4b0d8b-63ce-4407-b387-d08e240fd514" xlink:to="loc_shc_DebtInstrumentUnamortizedDiscountExcludingCurrentPortion_48b28ef9-ef25-4dad-b40d-44208aadf2d5" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnamortizedDiscountCurrent_f900ba0d-c99e-4cc1-b11b-d0bc8c3c01af" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentUnamortizedDiscountCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_db4b0d8b-63ce-4407-b387-d08e240fd514" xlink:to="loc_us-gaap_DebtInstrumentUnamortizedDiscountCurrent_f900ba0d-c99e-4cc1-b11b-d0bc8c3c01af" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebt_dc53fbc8-6a41-4fdb-9d84-7dcf1e610f3e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebt"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_db4b0d8b-63ce-4407-b387-d08e240fd514" xlink:to="loc_us-gaap_LongTermDebt_dc53fbc8-6a41-4fdb-9d84-7dcf1e610f3e" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtCurrent_8d4b0b53-108b-4c23-b2ea-9e26097edaf9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebtCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_db4b0d8b-63ce-4407-b387-d08e240fd514" xlink:to="loc_us-gaap_LongTermDebtCurrent_8d4b0b53-108b-4c23-b2ea-9e26097edaf9" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtNoncurrent_103e12d0-f08e-4f47-ad2d-d2f75d315b9c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebtNoncurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_db4b0d8b-63ce-4407-b387-d08e240fd514" xlink:to="loc_us-gaap_LongTermDebtNoncurrent_103e12d0-f08e-4f47-ad2d-d2f75d315b9c" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_b9ed3f6d-a4d9-416a-94a1-030cb310f5d7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_db4b0d8b-63ce-4407-b387-d08e240fd514" xlink:to="loc_us-gaap_DebtInstrumentTable_b9ed3f6d-a4d9-416a-94a1-030cb310f5d7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_2cfb55f2-30d0-4fa6-b123-e4b51097acf1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_b9ed3f6d-a4d9-416a-94a1-030cb310f5d7" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_2cfb55f2-30d0-4fa6-b123-e4b51097acf1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_2cfb55f2-30d0-4fa6-b123-e4b51097acf1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_2cfb55f2-30d0-4fa6-b123-e4b51097acf1" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_2cfb55f2-30d0-4fa6-b123-e4b51097acf1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_358b449b-4cec-4732-a78a-04917e29d76b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_2cfb55f2-30d0-4fa6-b123-e4b51097acf1" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_358b449b-4cec-4732-a78a-04917e29d76b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_TermLoanMember_175ecda5-0511-4e5b-a98e-2fea1f332ef5" xlink:href="shc-20230331.xsd#shc_TermLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_358b449b-4cec-4732-a78a-04917e29d76b" xlink:to="loc_shc_TermLoanMember_175ecda5-0511-4e5b-a98e-2fea1f332ef5" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_OtherLongTermDebtMember_29e46127-6ef7-49b8-b9f8-cf7fa5bb62fd" xlink:href="shc-20230331.xsd#shc_OtherLongTermDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_358b449b-4cec-4732-a78a-04917e29d76b" xlink:to="loc_shc_OtherLongTermDebtMember_29e46127-6ef7-49b8-b9f8-cf7fa5bb62fd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_efc27ff8-aad9-497b-b9cb-9b7c38bfb8d4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_b9ed3f6d-a4d9-416a-94a1-030cb310f5d7" xlink:to="loc_us-gaap_DebtInstrumentAxis_efc27ff8-aad9-497b-b9cb-9b7c38bfb8d4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_efc27ff8-aad9-497b-b9cb-9b7c38bfb8d4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_efc27ff8-aad9-497b-b9cb-9b7c38bfb8d4" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_efc27ff8-aad9-497b-b9cb-9b7c38bfb8d4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_54503ea8-53c0-4606-a7ed-4fcc5de68cca" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_efc27ff8-aad9-497b-b9cb-9b7c38bfb8d4" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_54503ea8-53c0-4606-a7ed-4fcc5de68cca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_TermLoanDue2026Member_b920c40f-ae5e-4e10-af1b-ab512e4076ce" xlink:href="shc-20230331.xsd#shc_TermLoanDue2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_54503ea8-53c0-4606-a7ed-4fcc5de68cca" xlink:to="loc_shc_TermLoanDue2026Member_b920c40f-ae5e-4e10-af1b-ab512e4076ce" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_TermLoanBDue2026Member_3469228d-9c28-4a75-ad79-c270699a2636" xlink:href="shc-20230331.xsd#shc_TermLoanBDue2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_54503ea8-53c0-4606-a7ed-4fcc5de68cca" xlink:to="loc_shc_TermLoanBDue2026Member_3469228d-9c28-4a75-ad79-c270699a2636" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_SeniorSecuredCreditFacilitiesMember_331691c1-bbdf-47ac-9214-e2827ddc94fc" xlink:href="shc-20230331.xsd#shc_SeniorSecuredCreditFacilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_54503ea8-53c0-4606-a7ed-4fcc5de68cca" xlink:to="loc_shc_SeniorSecuredCreditFacilitiesMember_331691c1-bbdf-47ac-9214-e2827ddc94fc" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_14afbfc7-b819-491a-be29-37a11b5ae566" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_b9ed3f6d-a4d9-416a-94a1-030cb310f5d7" xlink:to="loc_us-gaap_CreditFacilityAxis_14afbfc7-b819-491a-be29-37a11b5ae566" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_14afbfc7-b819-491a-be29-37a11b5ae566_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_14afbfc7-b819-491a-be29-37a11b5ae566" xlink:to="loc_us-gaap_CreditFacilityDomain_14afbfc7-b819-491a-be29-37a11b5ae566_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_1e3aa77c-9818-405f-a9b1-f735164057a1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_14afbfc7-b819-491a-be29-37a11b5ae566" xlink:to="loc_us-gaap_CreditFacilityDomain_1e3aa77c-9818-405f-a9b1-f735164057a1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_174211e0-705d-4e5e-bd4e-7beb34a7123a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_1e3aa77c-9818-405f-a9b1-f735164057a1" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_174211e0-705d-4e5e-bd4e-7beb34a7123a" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/LongTermDebtSeniorSecuredCreditFacilitiesNarrativeDetails" xlink:type="simple" xlink:href="shc-20230331.xsd#LongTermDebtSeniorSecuredCreditFacilitiesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/LongTermDebtSeniorSecuredCreditFacilitiesNarrativeDetails" xlink:type="extended" id="i6a286729a1c64e3ab8a0480cad01dd55_LongTermDebtSeniorSecuredCreditFacilitiesNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_e03924dd-2a7f-48ce-8d95-42c72c711658" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_780ff293-05d4-4c99-995d-1e3982929f66" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e03924dd-2a7f-48ce-8d95-42c72c711658" xlink:to="loc_us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_780ff293-05d4-4c99-995d-1e3982929f66" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentCarryingAmount_9b64ce67-41c0-46e5-ba6d-9b75940b0559" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentCarryingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e03924dd-2a7f-48ce-8d95-42c72c711658" xlink:to="loc_us-gaap_DebtInstrumentCarryingAmount_9b64ce67-41c0-46e5-ba6d-9b75940b0559" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateDuringPeriod_1f981f23-e940-4575-8731-97f1257fe1a2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentInterestRateDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e03924dd-2a7f-48ce-8d95-42c72c711658" xlink:to="loc_us-gaap_DebtInstrumentInterestRateDuringPeriod_1f981f23-e940-4575-8731-97f1257fe1a2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_09fe052a-f77a-4f96-8091-4cb9c59cf2d5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e03924dd-2a7f-48ce-8d95-42c72c711658" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_09fe052a-f77a-4f96-8091-4cb9c59cf2d5" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_DebtInstrumentPrepaymentPeriodWithoutPenalty_3aa09930-65ac-46fe-bae5-a4944f7c1828" xlink:href="shc-20230331.xsd#shc_DebtInstrumentPrepaymentPeriodWithoutPenalty"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e03924dd-2a7f-48ce-8d95-42c72c711658" xlink:to="loc_shc_DebtInstrumentPrepaymentPeriodWithoutPenalty_3aa09930-65ac-46fe-bae5-a4944f7c1828" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_DebtInstrumentPrincipalBalancePaymentPercentOfAmountOutstanding_f975b384-4051-4e09-b486-ad1595e1c95c" xlink:href="shc-20230331.xsd#shc_DebtInstrumentPrincipalBalancePaymentPercentOfAmountOutstanding"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e03924dd-2a7f-48ce-8d95-42c72c711658" xlink:to="loc_shc_DebtInstrumentPrincipalBalancePaymentPercentOfAmountOutstanding_f975b384-4051-4e09-b486-ad1595e1c95c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAnnualPrincipalPayment_774c8644-7f25-402f-b5ca-d7b8f9524273" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentAnnualPrincipalPayment"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e03924dd-2a7f-48ce-8d95-42c72c711658" xlink:to="loc_us-gaap_DebtInstrumentAnnualPrincipalPayment_774c8644-7f25-402f-b5ca-d7b8f9524273" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationSettlementAmountAwardedToOtherParty_47f3dfff-e629-49c7-a0b5-415b1500221b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LitigationSettlementAmountAwardedToOtherParty"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e03924dd-2a7f-48ce-8d95-42c72c711658" xlink:to="loc_us-gaap_LitigationSettlementAmountAwardedToOtherParty_47f3dfff-e629-49c7-a0b5-415b1500221b" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ExtinguishmentOfDebtAmount_bef5f082-eccd-43e7-be1f-bc8fc7b6c54a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ExtinguishmentOfDebtAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e03924dd-2a7f-48ce-8d95-42c72c711658" xlink:to="loc_us-gaap_ExtinguishmentOfDebtAmount_bef5f082-eccd-43e7-be1f-bc8fc7b6c54a" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LineOfCredit_2fd664ba-7e66-4f01-a0ab-d8cd27a3863d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LineOfCredit"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e03924dd-2a7f-48ce-8d95-42c72c711658" xlink:to="loc_us-gaap_LineOfCredit_2fd664ba-7e66-4f01-a0ab-d8cd27a3863d" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnamortizedDebtIssuanceExpense_85b71aa6-dc85-40ca-91e3-5126bf02cd26" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_UnamortizedDebtIssuanceExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e03924dd-2a7f-48ce-8d95-42c72c711658" xlink:to="loc_us-gaap_UnamortizedDebtIssuanceExpense_85b71aa6-dc85-40ca-91e3-5126bf02cd26" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_DebtInstrumentBaseAmountForDefault_f78f27c9-8d4d-42ed-8f8c-27344715f374" xlink:href="shc-20230331.xsd#shc_DebtInstrumentBaseAmountForDefault"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e03924dd-2a7f-48ce-8d95-42c72c711658" xlink:to="loc_shc_DebtInstrumentBaseAmountForDefault_f78f27c9-8d4d-42ed-8f8c-27344715f374" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_DebtInstrumentTriggeringPeriodForDefault_89af6e44-0724-45d8-95bc-745f79f6ae50" xlink:href="shc-20230331.xsd#shc_DebtInstrumentTriggeringPeriodForDefault"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e03924dd-2a7f-48ce-8d95-42c72c711658" xlink:to="loc_shc_DebtInstrumentTriggeringPeriodForDefault_89af6e44-0724-45d8-95bc-745f79f6ae50" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_151fa95b-4fe6-49ad-87e7-f3810ec80277" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LettersOfCreditOutstandingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e03924dd-2a7f-48ce-8d95-42c72c711658" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_151fa95b-4fe6-49ad-87e7-f3810ec80277" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount_01021082-7ded-43b1-b222-3facfb02ddb4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e03924dd-2a7f-48ce-8d95-42c72c711658" xlink:to="loc_us-gaap_DebtInstrumentUnusedBorrowingCapacityAmount_01021082-7ded-43b1-b222-3facfb02ddb4" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_4d368cd8-6f87-4e69-890a-5d4d0e433b03" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_e03924dd-2a7f-48ce-8d95-42c72c711658" xlink:to="loc_us-gaap_DebtInstrumentTable_4d368cd8-6f87-4e69-890a-5d4d0e433b03" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityAxis_64bbc3b3-bd26-452d-8763-8d3a832080b5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CreditFacilityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_4d368cd8-6f87-4e69-890a-5d4d0e433b03" xlink:to="loc_us-gaap_CreditFacilityAxis_64bbc3b3-bd26-452d-8763-8d3a832080b5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_64bbc3b3-bd26-452d-8763-8d3a832080b5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_CreditFacilityAxis_64bbc3b3-bd26-452d-8763-8d3a832080b5" xlink:to="loc_us-gaap_CreditFacilityDomain_64bbc3b3-bd26-452d-8763-8d3a832080b5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CreditFacilityDomain_ea05d62b-2496-421c-ae6a-fadae7bf7fb5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CreditFacilityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_CreditFacilityAxis_64bbc3b3-bd26-452d-8763-8d3a832080b5" xlink:to="loc_us-gaap_CreditFacilityDomain_ea05d62b-2496-421c-ae6a-fadae7bf7fb5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_f8d74845-bfa4-4776-aeba-35b170840ec2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_CreditFacilityDomain_ea05d62b-2496-421c-ae6a-fadae7bf7fb5" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_f8d74845-bfa4-4776-aeba-35b170840ec2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_1c10ca5d-b788-404a-b732-32a381d46911" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_4d368cd8-6f87-4e69-890a-5d4d0e433b03" xlink:to="loc_us-gaap_DebtInstrumentAxis_1c10ca5d-b788-404a-b732-32a381d46911" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_1c10ca5d-b788-404a-b732-32a381d46911_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_1c10ca5d-b788-404a-b732-32a381d46911" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_1c10ca5d-b788-404a-b732-32a381d46911_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_69371a79-a070-4ae6-a970-d6d5c3815d24" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_1c10ca5d-b788-404a-b732-32a381d46911" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_69371a79-a070-4ae6-a970-d6d5c3815d24" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_SeniorSecuredCreditFacilitiesMember_ae022633-266b-41c0-a2eb-d928abce9559" xlink:href="shc-20230331.xsd#shc_SeniorSecuredCreditFacilitiesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_69371a79-a070-4ae6-a970-d6d5c3815d24" xlink:to="loc_shc_SeniorSecuredCreditFacilitiesMember_ae022633-266b-41c0-a2eb-d928abce9559" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_TermLoanDue2026Member_00733761-c7bc-46aa-8029-52be3577a1d9" xlink:href="shc-20230331.xsd#shc_TermLoanDue2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_69371a79-a070-4ae6-a970-d6d5c3815d24" xlink:to="loc_shc_TermLoanDue2026Member_00733761-c7bc-46aa-8029-52be3577a1d9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_FirstLienNotesDue2026Member_d8abf41a-f37e-48cc-b631-7c3b706652b1" xlink:href="shc-20230331.xsd#shc_FirstLienNotesDue2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_69371a79-a070-4ae6-a970-d6d5c3815d24" xlink:to="loc_shc_FirstLienNotesDue2026Member_d8abf41a-f37e-48cc-b631-7c3b706652b1" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_TermLoanBDue2026Member_4a16ebf4-b8bb-4a2b-965e-41455ca3d20d" xlink:href="shc-20230331.xsd#shc_TermLoanBDue2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_69371a79-a070-4ae6-a970-d6d5c3815d24" xlink:to="loc_shc_TermLoanBDue2026Member_4a16ebf4-b8bb-4a2b-965e-41455ca3d20d" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_961773be-63e4-4fd6-b73b-e5d4f54a1869" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_4d368cd8-6f87-4e69-890a-5d4d0e433b03" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_961773be-63e4-4fd6-b73b-e5d4f54a1869" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_961773be-63e4-4fd6-b73b-e5d4f54a1869_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_961773be-63e4-4fd6-b73b-e5d4f54a1869" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_961773be-63e4-4fd6-b73b-e5d4f54a1869_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_7a74c512-5e87-4375-a15a-9294e19deec7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_961773be-63e4-4fd6-b73b-e5d4f54a1869" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_7a74c512-5e87-4375-a15a-9294e19deec7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_TermLoanMember_842579ce-78bf-49e4-9b7b-9b8299c64767" xlink:href="shc-20230331.xsd#shc_TermLoanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_7a74c512-5e87-4375-a15a-9294e19deec7" xlink:to="loc_shc_TermLoanMember_842579ce-78bf-49e4-9b7b-9b8299c64767" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_59d6e167-8e8a-49d2-8002-bf2aac6d0a76" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_7a74c512-5e87-4375-a15a-9294e19deec7" xlink:to="loc_us-gaap_SecuredDebtMember_59d6e167-8e8a-49d2-8002-bf2aac6d0a76" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_2e1d9a6e-ee37-463a-a2c6-24f32747581d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VariableRateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_4d368cd8-6f87-4e69-890a-5d4d0e433b03" xlink:to="loc_us-gaap_VariableRateAxis_2e1d9a6e-ee37-463a-a2c6-24f32747581d" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_2e1d9a6e-ee37-463a-a2c6-24f32747581d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_2e1d9a6e-ee37-463a-a2c6-24f32747581d" xlink:to="loc_us-gaap_VariableRateDomain_2e1d9a6e-ee37-463a-a2c6-24f32747581d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_884ef2f3-763c-47a4-86d9-ad85cf4dc166" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_2e1d9a6e-ee37-463a-a2c6-24f32747581d" xlink:to="loc_us-gaap_VariableRateDomain_884ef2f3-763c-47a4-86d9-ad85cf4dc166" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember_e38ae3ea-cbd7-47fc-a3df-e1dc781cafab" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_884ef2f3-763c-47a4-86d9-ad85cf4dc166" xlink:to="loc_us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember_e38ae3ea-cbd7-47fc-a3df-e1dc781cafab" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BaseRateMember_e21d4433-d4e1-4393-b227-93ef5ed78068" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BaseRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_884ef2f3-763c-47a4-86d9-ad85cf4dc166" xlink:to="loc_us-gaap_BaseRateMember_e21d4433-d4e1-4393-b227-93ef5ed78068" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseAxis_918a5c48-6601-45da-a6c5-fa1ce8757cfc" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_LitigationCaseAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_4d368cd8-6f87-4e69-890a-5d4d0e433b03" xlink:to="loc_srt_LitigationCaseAxis_918a5c48-6601-45da-a6c5-fa1ce8757cfc" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseTypeDomain_918a5c48-6601-45da-a6c5-fa1ce8757cfc_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_LitigationCaseTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_LitigationCaseAxis_918a5c48-6601-45da-a6c5-fa1ce8757cfc" xlink:to="loc_srt_LitigationCaseTypeDomain_918a5c48-6601-45da-a6c5-fa1ce8757cfc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseTypeDomain_6e9ca453-bfac-44ea-aeda-2db25b8034cf" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_LitigationCaseTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_LitigationCaseAxis_918a5c48-6601-45da-a6c5-fa1ce8757cfc" xlink:to="loc_srt_LitigationCaseTypeDomain_6e9ca453-bfac-44ea-aeda-2db25b8034cf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_AssetTransferCaseMemberMember_6012aaa5-eb88-4a1c-bd71-5c23537b12ce" xlink:href="shc-20230331.xsd#shc_AssetTransferCaseMemberMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_6e9ca453-bfac-44ea-aeda-2db25b8034cf" xlink:to="loc_shc_AssetTransferCaseMemberMember_6012aaa5-eb88-4a1c-bd71-5c23537b12ce" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_EthyleneOxideTortLitigationIllinoisMember_77c9ebe1-df02-44ab-9618-b8408d61a02d" xlink:href="shc-20230331.xsd#shc_EthyleneOxideTortLitigationIllinoisMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_6e9ca453-bfac-44ea-aeda-2db25b8034cf" xlink:to="loc_shc_EthyleneOxideTortLitigationIllinoisMember_77c9ebe1-df02-44ab-9618-b8408d61a02d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusAxis_7ac53fb4-5855-49eb-afbd-293f01f22a00" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LitigationStatusAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_4d368cd8-6f87-4e69-890a-5d4d0e433b03" xlink:to="loc_us-gaap_LitigationStatusAxis_7ac53fb4-5855-49eb-afbd-293f01f22a00" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusDomain_7ac53fb4-5855-49eb-afbd-293f01f22a00_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LitigationStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LitigationStatusAxis_7ac53fb4-5855-49eb-afbd-293f01f22a00" xlink:to="loc_us-gaap_LitigationStatusDomain_7ac53fb4-5855-49eb-afbd-293f01f22a00_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusDomain_b42d3154-cb05-428b-a835-c0980ff5d9d6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LitigationStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LitigationStatusAxis_7ac53fb4-5855-49eb-afbd-293f01f22a00" xlink:to="loc_us-gaap_LitigationStatusDomain_b42d3154-cb05-428b-a835-c0980ff5d9d6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PendingLitigationMember_f2042084-944e-4787-92f1-b4e4018edb2e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PendingLitigationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LitigationStatusDomain_b42d3154-cb05-428b-a835-c0980ff5d9d6" xlink:to="loc_us-gaap_PendingLitigationMember_f2042084-944e-4787-92f1-b4e4018edb2e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_56ef1105-0864-4439-9ec3-489240402ef5" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_4d368cd8-6f87-4e69-890a-5d4d0e433b03" xlink:to="loc_srt_RangeAxis_56ef1105-0864-4439-9ec3-489240402ef5" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_56ef1105-0864-4439-9ec3-489240402ef5_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_56ef1105-0864-4439-9ec3-489240402ef5" xlink:to="loc_srt_RangeMember_56ef1105-0864-4439-9ec3-489240402ef5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_38679e9f-cd89-4e75-9c9d-7962cff6e652" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_56ef1105-0864-4439-9ec3-489240402ef5" xlink:to="loc_srt_RangeMember_38679e9f-cd89-4e75-9c9d-7962cff6e652" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_1a223fa7-7fea-401f-8647-18257af7cb4c" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_38679e9f-cd89-4e75-9c9d-7962cff6e652" xlink:to="loc_srt_MinimumMember_1a223fa7-7fea-401f-8647-18257af7cb4c" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/LongTermDebtFirstLienNotesNarrativeDetails" xlink:type="simple" xlink:href="shc-20230331.xsd#LongTermDebtFirstLienNotesNarrativeDetails"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/LongTermDebtFirstLienNotesNarrativeDetails" xlink:type="extended" id="i6e822991b73c46c9a50c7e2d9185fd67_LongTermDebtFirstLienNotesNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentLineItems_ec6d8a0b-722b-4f4a-99da-e772d7690e85" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_a4f641f2-efc0-4955-a27e-45b0d2035a97" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ec6d8a0b-722b-4f4a-99da-e772d7690e85" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_a4f641f2-efc0-4955-a27e-45b0d2035a97" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_c7dfcb5a-c0ad-4862-bd65-5bf1ad68fad2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ec6d8a0b-722b-4f4a-99da-e772d7690e85" xlink:to="loc_us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_c7dfcb5a-c0ad-4862-bd65-5bf1ad68fad2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentInterestRateDuringPeriod_0e521184-e0cd-4309-a294-cfea634db36f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentInterestRateDuringPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ec6d8a0b-722b-4f4a-99da-e772d7690e85" xlink:to="loc_us-gaap_DebtInstrumentInterestRateDuringPeriod_0e521184-e0cd-4309-a294-cfea634db36f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentTable_39f2da76-7c77-4c46-af20-f21f23605094" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DebtInstrumentLineItems_ec6d8a0b-722b-4f4a-99da-e772d7690e85" xlink:to="loc_us-gaap_DebtInstrumentTable_39f2da76-7c77-4c46-af20-f21f23605094" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_a655f505-6f0d-4c34-9d4a-fd847b1d1a41" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_39f2da76-7c77-4c46-af20-f21f23605094" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_a655f505-6f0d-4c34-9d4a-fd847b1d1a41" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_a655f505-6f0d-4c34-9d4a-fd847b1d1a41_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_a655f505-6f0d-4c34-9d4a-fd847b1d1a41" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_a655f505-6f0d-4c34-9d4a-fd847b1d1a41_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_1b9833c4-49a1-48d5-8e27-0c577a0546ca" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_a655f505-6f0d-4c34-9d4a-fd847b1d1a41" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_1b9833c4-49a1-48d5-8e27-0c577a0546ca" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_510a6c20-2597-4f74-9a2d-f1bdac28dd51" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_1b9833c4-49a1-48d5-8e27-0c577a0546ca" xlink:to="loc_us-gaap_SecuredDebtMember_510a6c20-2597-4f74-9a2d-f1bdac28dd51" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_8c52cae5-c585-4a70-a117-46bc22b4dec5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_39f2da76-7c77-4c46-af20-f21f23605094" xlink:to="loc_us-gaap_DebtInstrumentAxis_8c52cae5-c585-4a70-a117-46bc22b4dec5" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_8c52cae5-c585-4a70-a117-46bc22b4dec5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_8c52cae5-c585-4a70-a117-46bc22b4dec5" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_8c52cae5-c585-4a70-a117-46bc22b4dec5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_18214e05-4cbb-460f-8c28-d9feafad4850" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_8c52cae5-c585-4a70-a117-46bc22b4dec5" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_18214e05-4cbb-460f-8c28-d9feafad4850" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_FirstLienNotesDue2026Member_c2bc02b6-dbd4-4351-8275-51769e73730b" xlink:href="shc-20230331.xsd#shc_FirstLienNotesDue2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_18214e05-4cbb-460f-8c28-d9feafad4850" xlink:to="loc_shc_FirstLienNotesDue2026Member_c2bc02b6-dbd4-4351-8275-51769e73730b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_67ebe26d-504e-4770-ab0b-2a4dfa28ea27" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VariableRateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DebtInstrumentTable_39f2da76-7c77-4c46-af20-f21f23605094" xlink:to="loc_us-gaap_VariableRateAxis_67ebe26d-504e-4770-ab0b-2a4dfa28ea27" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_67ebe26d-504e-4770-ab0b-2a4dfa28ea27_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_67ebe26d-504e-4770-ab0b-2a4dfa28ea27" xlink:to="loc_us-gaap_VariableRateDomain_67ebe26d-504e-4770-ab0b-2a4dfa28ea27_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_b89b583f-2c83-4b8d-9fe3-87b38f8fad07" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_67ebe26d-504e-4770-ab0b-2a4dfa28ea27" xlink:to="loc_us-gaap_VariableRateDomain_b89b583f-2c83-4b8d-9fe3-87b38f8fad07" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_3f23b772-328b-46e5-95b5-144b820f38f0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LondonInterbankOfferedRateLIBORMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_b89b583f-2c83-4b8d-9fe3-87b38f8fad07" xlink:to="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_3f23b772-328b-46e5-95b5-144b820f38f0" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/EmployeeBenefitsScheduleofNetPeriodicBenefitCostsDetails" xlink:type="simple" xlink:href="shc-20230331.xsd#EmployeeBenefitsScheduleofNetPeriodicBenefitCostsDetails"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/EmployeeBenefitsScheduleofNetPeriodicBenefitCostsDetails" xlink:type="extended" id="ie929a956d7cc4fddb15b9f36d8a77c0d_EmployeeBenefitsScheduleofNetPeriodicBenefitCostsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_32f3375d-10da-429d-8c2a-ae42327698ca" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanServiceCost_6e2ef57c-ef5f-47b9-87de-4220a1cea73a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DefinedBenefitPlanServiceCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_32f3375d-10da-429d-8c2a-ae42327698ca" xlink:to="loc_us-gaap_DefinedBenefitPlanServiceCost_6e2ef57c-ef5f-47b9-87de-4220a1cea73a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanInterestCost_b7946658-54a9-422e-86f2-dde38070d06e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DefinedBenefitPlanInterestCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_32f3375d-10da-429d-8c2a-ae42327698ca" xlink:to="loc_us-gaap_DefinedBenefitPlanInterestCost_b7946658-54a9-422e-86f2-dde38070d06e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_9176dc27-6095-45bf-8c2a-d416e791dfe8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_32f3375d-10da-429d-8c2a-ae42327698ca" xlink:to="loc_us-gaap_DefinedBenefitPlanExpectedReturnOnPlanAssets_9176dc27-6095-45bf-8c2a-d416e791dfe8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_de47a9d6-9f62-457c-a475-83e7319cd03f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_32f3375d-10da-429d-8c2a-ae42327698ca" xlink:to="loc_us-gaap_DefinedBenefitPlanAmortizationOfGainsLosses_de47a9d6-9f62-457c-a475-83e7319cd03f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_4a334040-0150-4e75-a911-1832419b3ba8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_32f3375d-10da-429d-8c2a-ae42327698ca" xlink:to="loc_us-gaap_DefinedBenefitPlanNetPeriodicBenefitCost_4a334040-0150-4e75-a911-1832419b3ba8" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_d3553f1e-7581-4e30-8d33-df6af89e5b02" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_32f3375d-10da-429d-8c2a-ae42327698ca" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_d3553f1e-7581-4e30-8d33-df6af89e5b02" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_ec0c4dd9-9422-4e0a-b26a-539fb8a62c80" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_d3553f1e-7581-4e30-8d33-df6af89e5b02" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_ec0c4dd9-9422-4e0a-b26a-539fb8a62c80" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_ec0c4dd9-9422-4e0a-b26a-539fb8a62c80_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_ec0c4dd9-9422-4e0a-b26a-539fb8a62c80" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_ec0c4dd9-9422-4e0a-b26a-539fb8a62c80_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_7634f43c-6c41-4548-9b11-72153f113755" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_ec0c4dd9-9422-4e0a-b26a-539fb8a62c80" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_7634f43c-6c41-4548-9b11-72153f113755" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_b076ee1b-59a9-407e-99ae-43e8f04f766c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_7634f43c-6c41-4548-9b11-72153f113755" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_b076ee1b-59a9-407e-99ae-43e8f04f766c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_b0382ca1-9c26-4150-9d18-a9b2007a524e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_7634f43c-6c41-4548-9b11-72153f113755" xlink:to="loc_us-gaap_OtherPostretirementBenefitPlansDefinedBenefitMember_b0382ca1-9c26-4150-9d18-a9b2007a524e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_cf54ae18-7c95-4c56-9415-7992d3405503" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_d3553f1e-7581-4e30-8d33-df6af89e5b02" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_cf54ae18-7c95-4c56-9415-7992d3405503" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_cf54ae18-7c95-4c56-9415-7992d3405503_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_cf54ae18-7c95-4c56-9415-7992d3405503" xlink:to="loc_us-gaap_SegmentDomain_cf54ae18-7c95-4c56-9415-7992d3405503_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_304d6a3a-38cd-44b7-ac90-b774d2e48096" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_cf54ae18-7c95-4c56-9415-7992d3405503" xlink:to="loc_us-gaap_SegmentDomain_304d6a3a-38cd-44b7-ac90-b774d2e48096" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_NordionMember_1f108312-bc63-454c-b5a7-cca0019ab85c" xlink:href="shc-20230331.xsd#shc_NordionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_304d6a3a-38cd-44b7-ac90-b774d2e48096" xlink:to="loc_shc_NordionMember_1f108312-bc63-454c-b5a7-cca0019ab85c" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/EmployeeBenefitsNarrativeDetails" xlink:type="simple" xlink:href="shc-20230331.xsd#EmployeeBenefitsNarrativeDetails"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/EmployeeBenefitsNarrativeDetails" xlink:type="extended" id="if87587c8feb64d0289c782717e5ee3a0_EmployeeBenefitsNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0b1ed6cc-1c02-4bd7-8202-df736be1ead8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DefinedBenefitPlanDisclosureLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_DefinedBenefitPlanAnnualFundingRequirementsForNextFiveYears_c9eb8296-8a83-4e27-a379-15886091f6f2" xlink:href="shc-20230331.xsd#shc_DefinedBenefitPlanAnnualFundingRequirementsForNextFiveYears"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0b1ed6cc-1c02-4bd7-8202-df736be1ead8" xlink:to="loc_shc_DefinedBenefitPlanAnnualFundingRequirementsForNextFiveYears_c9eb8296-8a83-4e27-a379-15886091f6f2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_LettersOfCreditSolvencyPaymentAsPercentOfMarketValue_44bcec9c-3f3c-4954-828c-da906a6b1882" xlink:href="shc-20230331.xsd#shc_LettersOfCreditSolvencyPaymentAsPercentOfMarketValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0b1ed6cc-1c02-4bd7-8202-df736be1ead8" xlink:to="loc_shc_LettersOfCreditSolvencyPaymentAsPercentOfMarketValue_44bcec9c-3f3c-4954-828c-da906a6b1882" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LettersOfCreditOutstandingAmount_d95d4654-74b6-45d9-a410-c809c080ad40" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LettersOfCreditOutstandingAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0b1ed6cc-1c02-4bd7-8202-df736be1ead8" xlink:to="loc_us-gaap_LettersOfCreditOutstandingAmount_d95d4654-74b6-45d9-a410-c809c080ad40" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_2dc3d88d-8418-4c4f-8b19-f762f7e147ce" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DefinedBenefitPlanDisclosureLineItems_0b1ed6cc-1c02-4bd7-8202-df736be1ead8" xlink:to="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_2dc3d88d-8418-4c4f-8b19-f762f7e147ce" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_9140851c-1bc3-4299-96ad-1f084cfe5ad9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_2dc3d88d-8418-4c4f-8b19-f762f7e147ce" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_9140851c-1bc3-4299-96ad-1f084cfe5ad9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_9140851c-1bc3-4299-96ad-1f084cfe5ad9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_9140851c-1bc3-4299-96ad-1f084cfe5ad9" xlink:to="loc_us-gaap_SegmentDomain_9140851c-1bc3-4299-96ad-1f084cfe5ad9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_bef19cf5-5373-4dee-929b-0cd2905610f6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_9140851c-1bc3-4299-96ad-1f084cfe5ad9" xlink:to="loc_us-gaap_SegmentDomain_bef19cf5-5373-4dee-929b-0cd2905610f6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_NordionMember_8d9c861e-ca27-40f7-825b-6ec9aaa757c9" xlink:href="shc-20230331.xsd#shc_NordionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_bef19cf5-5373-4dee-929b-0cd2905610f6" xlink:to="loc_shc_NordionMember_8d9c861e-ca27-40f7-825b-6ec9aaa757c9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeAxis_72bf0815-4615-4296-9ffb-c8f7ddf2bb3c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_2dc3d88d-8418-4c4f-8b19-f762f7e147ce" xlink:to="loc_us-gaap_RetirementPlanTypeAxis_72bf0815-4615-4296-9ffb-c8f7ddf2bb3c" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_72bf0815-4615-4296-9ffb-c8f7ddf2bb3c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_72bf0815-4615-4296-9ffb-c8f7ddf2bb3c" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_72bf0815-4615-4296-9ffb-c8f7ddf2bb3c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RetirementPlanTypeDomain_2e652372-0b6f-4551-80a1-cbdc2336c847" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RetirementPlanTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_RetirementPlanTypeAxis_72bf0815-4615-4296-9ffb-c8f7ddf2bb3c" xlink:to="loc_us-gaap_RetirementPlanTypeDomain_2e652372-0b6f-4551-80a1-cbdc2336c847" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PensionPlansDefinedBenefitMember_6fd0d05e-5eae-4dc6-a7b5-2d2fea4af407" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PensionPlansDefinedBenefitMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_RetirementPlanTypeDomain_2e652372-0b6f-4551-80a1-cbdc2336c847" xlink:to="loc_us-gaap_PensionPlansDefinedBenefitMember_6fd0d05e-5eae-4dc6-a7b5-2d2fea4af407" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_b65396af-e7cb-4676-8fbd-cf7489e08377" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfDefinedBenefitPlansDisclosuresTable_2dc3d88d-8418-4c4f-8b19-f762f7e147ce" xlink:to="loc_srt_RangeAxis_b65396af-e7cb-4676-8fbd-cf7489e08377" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_b65396af-e7cb-4676-8fbd-cf7489e08377_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_b65396af-e7cb-4676-8fbd-cf7489e08377" xlink:to="loc_srt_RangeMember_b65396af-e7cb-4676-8fbd-cf7489e08377_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_2f306422-9c73-40b5-a5a6-1cac53dbc6c0" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_b65396af-e7cb-4676-8fbd-cf7489e08377" xlink:to="loc_srt_RangeMember_2f306422-9c73-40b5-a5a6-1cac53dbc6c0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_9fef7c22-033e-4c93-9fec-c90b1b9d337c" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_2f306422-9c73-40b5-a5a6-1cac53dbc6c0" xlink:to="loc_srt_MaximumMember_9fef7c22-033e-4c93-9fec-c90b1b9d337c" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/OtherComprehensiveIncomeLossDetails" xlink:type="simple" xlink:href="shc-20230331.xsd#OtherComprehensiveIncomeLossDetails"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/OtherComprehensiveIncomeLossDetails" xlink:type="extended" id="ibc1ca747fd77476cbdd7fd05a64b22a1_OtherComprehensiveIncomeLossDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_d7e80e6d-cc0d-4365-9918-1eee90ccdcc3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_dc914608-b7e0-4da5-b6c7-2f3ee2377514" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquity"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_d7e80e6d-cc0d-4365-9918-1eee90ccdcc3" xlink:to="loc_us-gaap_StockholdersEquity_dc914608-b7e0-4da5-b6c7-2f3ee2377514" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_77702bd5-2446-4cc5-bcf8-b9187ac43ca3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_d7e80e6d-cc0d-4365-9918-1eee90ccdcc3" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossBeforeReclassificationsNetOfTax_77702bd5-2446-4cc5-bcf8-b9187ac43ca3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_d0836179-d839-4251-8f38-cd73a70f725a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_d7e80e6d-cc0d-4365-9918-1eee90ccdcc3" xlink:to="loc_us-gaap_ReclassificationFromAccumulatedOtherComprehensiveIncomeCurrentPeriodNetOfTax_d0836179-d839-4251-8f38-cd73a70f725a" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_d5fc7a3f-3b34-4a1e-a837-3c6ed1154393" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherComprehensiveIncomeLossNetOfTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_d7e80e6d-cc0d-4365-9918-1eee90ccdcc3" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossNetOfTax_d5fc7a3f-3b34-4a1e-a837-3c6ed1154393" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockholdersEquity_62330cf6-217b-4503-9fc3-e9f78f86f74c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockholdersEquity"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_171392a5-783e-4d4f-a333-ce49e530931d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossLineItems_d7e80e6d-cc0d-4365-9918-1eee90ccdcc3" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_171392a5-783e-4d4f-a333-ce49e530931d" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementEquityComponentsAxis_965a2a54-c2ba-4b45-a342-8ea0798907d2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementEquityComponentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_171392a5-783e-4d4f-a333-ce49e530931d" xlink:to="loc_us-gaap_StatementEquityComponentsAxis_965a2a54-c2ba-4b45-a342-8ea0798907d2" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_965a2a54-c2ba-4b45-a342-8ea0798907d2_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_965a2a54-c2ba-4b45-a342-8ea0798907d2" xlink:to="loc_us-gaap_EquityComponentDomain_965a2a54-c2ba-4b45-a342-8ea0798907d2_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EquityComponentDomain_2b6e7861-e93a-42fd-8474-d4a28eee282f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EquityComponentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementEquityComponentsAxis_965a2a54-c2ba-4b45-a342-8ea0798907d2" xlink:to="loc_us-gaap_EquityComponentDomain_2b6e7861-e93a-42fd-8474-d4a28eee282f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_8581fc0f-1afc-4544-a90a-964f0a34d9b4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_EquityComponentDomain_2b6e7861-e93a-42fd-8474-d4a28eee282f" xlink:to="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_8581fc0f-1afc-4544-a90a-964f0a34d9b4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_de6f7c45-3afb-42eb-8c08-7e58fe334c15" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_8581fc0f-1afc-4544-a90a-964f0a34d9b4" xlink:to="loc_us-gaap_AccumulatedDefinedBenefitPlansAdjustmentMember_de6f7c45-3afb-42eb-8c08-7e58fe334c15" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedTranslationAdjustmentMember_1890857c-9ec8-49ad-855a-dc92933e646f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedTranslationAdjustmentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_8581fc0f-1afc-4544-a90a-964f0a34d9b4" xlink:to="loc_us-gaap_AccumulatedTranslationAdjustmentMember_1890857c-9ec8-49ad-855a-dc92933e646f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_9420606e-029e-49e7-aa83-f0b5f953f440" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_AccumulatedOtherComprehensiveIncomeMember_8581fc0f-1afc-4544-a90a-964f0a34d9b4" xlink:to="loc_us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_9420606e-029e-49e7-aa83-f0b5f953f440" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/ShareBasedCompensationNarrativeDetails" xlink:type="simple" xlink:href="shc-20230331.xsd#ShareBasedCompensationNarrativeDetails"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/ShareBasedCompensationNarrativeDetails" xlink:type="extended" id="icf0048ad01e8431faa0c07a6469a80eb_ShareBasedCompensationNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_70538a1c-28aa-4015-a3f4-aec108aa5b0f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_2eb1b728-ff1d-4031-8513-409fe48db57a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_70538a1c-28aa-4015-a3f4-aec108aa5b0f" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_2eb1b728-ff1d-4031-8513-409fe48db57a" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_8db683f5-4717-48ed-8454-72779202b0a3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_70538a1c-28aa-4015-a3f4-aec108aa5b0f" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardAwardVestingRightsPercentage_8db683f5-4717-48ed-8454-72779202b0a3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_PercentOfReturnOnInvestments_75f98add-ec6d-4654-9e29-d005ed9cc87b" xlink:href="shc-20230331.xsd#shc_PercentOfReturnOnInvestments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_70538a1c-28aa-4015-a3f4-aec108aa5b0f" xlink:to="loc_shc_PercentOfReturnOnInvestments_75f98add-ec6d-4654-9e29-d005ed9cc87b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllocatedShareBasedCompensationExpense_ce894dd4-d8fd-431a-a95d-ae1658353109" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AllocatedShareBasedCompensationExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_70538a1c-28aa-4015-a3f4-aec108aa5b0f" xlink:to="loc_us-gaap_AllocatedShareBasedCompensationExpense_ce894dd4-d8fd-431a-a95d-ae1658353109" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_0e1a9c7f-b275-47de-8ed0-d0ea4c3a8d7b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_70538a1c-28aa-4015-a3f4-aec108aa5b0f" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_0e1a9c7f-b275-47de-8ed0-d0ea4c3a8d7b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1_c4587969-4fc7-4e93-8144-07ff0885ea1b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_70538a1c-28aa-4015-a3f4-aec108aa5b0f" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsVestedInPeriodFairValue1_c4587969-4fc7-4e93-8144-07ff0885ea1b" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableInPeriodFairValue_42c907d1-ef12-4c20-b081-a8dcc0297ef0" xlink:href="shc-20230331.xsd#shc_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableInPeriodFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_70538a1c-28aa-4015-a3f4-aec108aa5b0f" xlink:to="loc_shc_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableInPeriodFairValue_42c907d1-ef12-4c20-b081-a8dcc0297ef0" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_fe24bbbe-3b02-4f36-a35c-51d30cf924c6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_70538a1c-28aa-4015-a3f4-aec108aa5b0f" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_fe24bbbe-3b02-4f36-a35c-51d30cf924c6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_3ba969e1-1f34-4246-a791-cea526f83b8a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_fe24bbbe-3b02-4f36-a35c-51d30cf924c6" xlink:to="loc_us-gaap_AwardTypeAxis_3ba969e1-1f34-4246-a791-cea526f83b8a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_3ba969e1-1f34-4246-a791-cea526f83b8a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_3ba969e1-1f34-4246-a791-cea526f83b8a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_3ba969e1-1f34-4246-a791-cea526f83b8a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8b0027cd-12d9-49ff-a117-a7a1230f3a20" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_3ba969e1-1f34-4246-a791-cea526f83b8a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8b0027cd-12d9-49ff-a117-a7a1230f3a20" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_ae679b0e-bcd5-4678-9486-7bde9d7eede4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8b0027cd-12d9-49ff-a117-a7a1230f3a20" xlink:to="loc_us-gaap_RestrictedStockMember_ae679b0e-bcd5-4678-9486-7bde9d7eede4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_858c0187-b6e8-4780-ab61-a9b3663f1987" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8b0027cd-12d9-49ff-a117-a7a1230f3a20" xlink:to="loc_us-gaap_EmployeeStockOptionMember_858c0187-b6e8-4780-ab61-a9b3663f1987" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_9b8d834d-bfe8-4b20-8629-b2f28f2ce74b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_8b0027cd-12d9-49ff-a117-a7a1230f3a20" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_9b8d834d-bfe8-4b20-8629-b2f28f2ce74b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_98d0b3f2-9ba0-427a-90d7-57a48dc1cdc9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_fe24bbbe-3b02-4f36-a35c-51d30cf924c6" xlink:to="loc_us-gaap_StatementClassOfStockAxis_98d0b3f2-9ba0-427a-90d7-57a48dc1cdc9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_98d0b3f2-9ba0-427a-90d7-57a48dc1cdc9_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_98d0b3f2-9ba0-427a-90d7-57a48dc1cdc9" xlink:to="loc_us-gaap_ClassOfStockDomain_98d0b3f2-9ba0-427a-90d7-57a48dc1cdc9_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_914ace0d-a523-4231-b16b-a351108fcc9f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_98d0b3f2-9ba0-427a-90d7-57a48dc1cdc9" xlink:to="loc_us-gaap_ClassOfStockDomain_914ace0d-a523-4231-b16b-a351108fcc9f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_PreIPOB1Member_6e10066d-b4a0-4626-8a56-c316313f27f8" xlink:href="shc-20230331.xsd#shc_PreIPOB1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_914ace0d-a523-4231-b16b-a351108fcc9f" xlink:to="loc_shc_PreIPOB1Member_6e10066d-b4a0-4626-8a56-c316313f27f8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_PreIPOB2Member_479c0399-55f3-4328-a9d1-9db986ba00d3" xlink:href="shc-20230331.xsd#shc_PreIPOB2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_914ace0d-a523-4231-b16b-a351108fcc9f" xlink:to="loc_shc_PreIPOB2Member_479c0399-55f3-4328-a9d1-9db986ba00d3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingAxis_8362566c-e577-4ab2-9ef0-3338e6422bb6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VestingAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_fe24bbbe-3b02-4f36-a35c-51d30cf924c6" xlink:to="loc_us-gaap_VestingAxis_8362566c-e577-4ab2-9ef0-3338e6422bb6" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingDomain_8362566c-e577-4ab2-9ef0-3338e6422bb6_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VestingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VestingAxis_8362566c-e577-4ab2-9ef0-3338e6422bb6" xlink:to="loc_us-gaap_VestingDomain_8362566c-e577-4ab2-9ef0-3338e6422bb6_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VestingDomain_8f4fd749-3654-485e-aca3-cdfc0e675115" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VestingDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VestingAxis_8362566c-e577-4ab2-9ef0-3338e6422bb6" xlink:to="loc_us-gaap_VestingDomain_8f4fd749-3654-485e-aca3-cdfc0e675115" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheOneMember_1271a62b-02d9-4bee-a975-3eee8ade74db" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationAwardTrancheOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VestingDomain_8f4fd749-3654-485e-aca3-cdfc0e675115" xlink:to="loc_us-gaap_ShareBasedCompensationAwardTrancheOneMember_1271a62b-02d9-4bee-a975-3eee8ade74db" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheTwoMember_bc87ad41-da58-449f-bb1f-963a881af06d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationAwardTrancheTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VestingDomain_8f4fd749-3654-485e-aca3-cdfc0e675115" xlink:to="loc_us-gaap_ShareBasedCompensationAwardTrancheTwoMember_bc87ad41-da58-449f-bb1f-963a881af06d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationAwardTrancheThreeMember_a37e952f-b671-4170-b062-205748debfd3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationAwardTrancheThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VestingDomain_8f4fd749-3654-485e-aca3-cdfc0e675115" xlink:to="loc_us-gaap_ShareBasedCompensationAwardTrancheThreeMember_a37e952f-b671-4170-b062-205748debfd3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_ShareBasedPaymentArrangementTrancheFourMember_00b9e4f8-7a7d-41ea-b3b3-afd93157a749" xlink:href="shc-20230331.xsd#shc_ShareBasedPaymentArrangementTrancheFourMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VestingDomain_8f4fd749-3654-485e-aca3-cdfc0e675115" xlink:to="loc_shc_ShareBasedPaymentArrangementTrancheFourMember_00b9e4f8-7a7d-41ea-b3b3-afd93157a749" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_ShareBasedPaymentArrangementTrancheFiveMember_392f071a-0eb4-48d0-a6fc-a67598a42a80" xlink:href="shc-20230331.xsd#shc_ShareBasedPaymentArrangementTrancheFiveMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VestingDomain_8f4fd749-3654-485e-aca3-cdfc0e675115" xlink:to="loc_shc_ShareBasedPaymentArrangementTrancheFiveMember_392f071a-0eb4-48d0-a6fc-a67598a42a80" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameAxis_b0b05f3b-f633-475a-b63c-1d46312cc56b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PlanNameAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_fe24bbbe-3b02-4f36-a35c-51d30cf924c6" xlink:to="loc_us-gaap_PlanNameAxis_b0b05f3b-f633-475a-b63c-1d46312cc56b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_b0b05f3b-f633-475a-b63c-1d46312cc56b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_PlanNameAxis_b0b05f3b-f633-475a-b63c-1d46312cc56b" xlink:to="loc_us-gaap_PlanNameDomain_b0b05f3b-f633-475a-b63c-1d46312cc56b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PlanNameDomain_dc8d11d6-ba9f-4d33-afe9-0445ea907e2b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_PlanNameAxis_b0b05f3b-f633-475a-b63c-1d46312cc56b" xlink:to="loc_us-gaap_PlanNameDomain_dc8d11d6-ba9f-4d33-afe9-0445ea907e2b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_A2020OmnibusIncentivePlanMember_0be6fe4b-8b45-4875-bb0c-250c65e32ff6" xlink:href="shc-20230331.xsd#shc_A2020OmnibusIncentivePlanMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PlanNameDomain_dc8d11d6-ba9f-4d33-afe9-0445ea907e2b" xlink:to="loc_shc_A2020OmnibusIncentivePlanMember_0be6fe4b-8b45-4875-bb0c-250c65e32ff6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_f6e83ba6-ce45-4440-8dd9-080f3044a32f" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_fe24bbbe-3b02-4f36-a35c-51d30cf924c6" xlink:to="loc_srt_RangeAxis_f6e83ba6-ce45-4440-8dd9-080f3044a32f" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_f6e83ba6-ce45-4440-8dd9-080f3044a32f_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_f6e83ba6-ce45-4440-8dd9-080f3044a32f" xlink:to="loc_srt_RangeMember_f6e83ba6-ce45-4440-8dd9-080f3044a32f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_ddade9f7-0445-47b5-a973-fbf1c1c6b80e" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_f6e83ba6-ce45-4440-8dd9-080f3044a32f" xlink:to="loc_srt_RangeMember_ddade9f7-0445-47b5-a973-fbf1c1c6b80e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_2905a8ec-54b0-4dcb-82ed-ec918cb65e1c" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_ddade9f7-0445-47b5-a973-fbf1c1c6b80e" xlink:to="loc_srt_MinimumMember_2905a8ec-54b0-4dcb-82ed-ec918cb65e1c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MaximumMember_44050221-37e1-4059-b4f7-70e3967824a4" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MaximumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_ddade9f7-0445-47b5-a973-fbf1c1c6b80e" xlink:to="loc_srt_MaximumMember_44050221-37e1-4059-b4f7-70e3967824a4" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/ShareBasedCompensationScheduleofNonvestedRestrictedStockUnitsActivityDetails" xlink:type="simple" xlink:href="shc-20230331.xsd#ShareBasedCompensationScheduleofNonvestedRestrictedStockUnitsActivityDetails"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/ShareBasedCompensationScheduleofNonvestedRestrictedStockUnitsActivityDetails" xlink:type="extended" id="i68385b8bfee742d5972ed46dbe64b184_ShareBasedCompensationScheduleofNonvestedRestrictedStockUnitsActivityDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_5c58774a-6e3d-41d2-ba8c-ed8faeeeeb1a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_0becb767-8302-4c09-bf02-b9755f335f42" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_5c58774a-6e3d-41d2-ba8c-ed8faeeeeb1a" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_0becb767-8302-4c09-bf02-b9755f335f42" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_37cbae55-0f2e-4e12-9978-883a15a65bf6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_0becb767-8302-4c09-bf02-b9755f335f42" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_37cbae55-0f2e-4e12-9978-883a15a65bf6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_e7958e4e-0627-42e8-a4ee-9ce9b8d39430" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_0becb767-8302-4c09-bf02-b9755f335f42" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_e7958e4e-0627-42e8-a4ee-9ce9b8d39430" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_dd1deab2-5f99-42ce-b7e4-18f98a1691ec" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_0becb767-8302-4c09-bf02-b9755f335f42" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_dd1deab2-5f99-42ce-b7e4-18f98a1691ec" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_89162399-bce1-4382-beaa-50aae2085cce" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_419a8c2c-a8cf-4b16-af4c-867d9ab4c63b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_5c58774a-6e3d-41d2-ba8c-ed8faeeeeb1a" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_419a8c2c-a8cf-4b16-af4c-867d9ab4c63b" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_ae293024-34a5-4ac3-8786-d98491bd3081" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_419a8c2c-a8cf-4b16-af4c-867d9ab4c63b" xlink:to="loc_us-gaap_AwardTypeAxis_ae293024-34a5-4ac3-8786-d98491bd3081" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_ae293024-34a5-4ac3-8786-d98491bd3081_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_ae293024-34a5-4ac3-8786-d98491bd3081" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_ae293024-34a5-4ac3-8786-d98491bd3081_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_dce9258c-1046-4607-ade1-26d6ae7fdbc0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_ae293024-34a5-4ac3-8786-d98491bd3081" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_dce9258c-1046-4607-ade1-26d6ae7fdbc0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockMember_8dd6cca5-ab08-4439-9a9b-57f22acf4b6d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestrictedStockMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_dce9258c-1046-4607-ade1-26d6ae7fdbc0" xlink:to="loc_us-gaap_RestrictedStockMember_8dd6cca5-ab08-4439-9a9b-57f22acf4b6d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementClassOfStockAxis_04dc643e-703e-4597-8f82-e88fdcb64375" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementClassOfStockAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_419a8c2c-a8cf-4b16-af4c-867d9ab4c63b" xlink:to="loc_us-gaap_StatementClassOfStockAxis_04dc643e-703e-4597-8f82-e88fdcb64375" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_04dc643e-703e-4597-8f82-e88fdcb64375_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementClassOfStockAxis_04dc643e-703e-4597-8f82-e88fdcb64375" xlink:to="loc_us-gaap_ClassOfStockDomain_04dc643e-703e-4597-8f82-e88fdcb64375_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ClassOfStockDomain_231672bf-52ad-4bbe-9eab-8f7ccfe36574" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ClassOfStockDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementClassOfStockAxis_04dc643e-703e-4597-8f82-e88fdcb64375" xlink:to="loc_us-gaap_ClassOfStockDomain_231672bf-52ad-4bbe-9eab-8f7ccfe36574" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_PreIPOB1Member_e761681b-aff0-4971-a8c1-f312bd910197" xlink:href="shc-20230331.xsd#shc_PreIPOB1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_231672bf-52ad-4bbe-9eab-8f7ccfe36574" xlink:to="loc_shc_PreIPOB1Member_e761681b-aff0-4971-a8c1-f312bd910197" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_PreIPOB2Member_1dcb03d5-bb0a-4ad2-806e-7177226b132e" xlink:href="shc-20230331.xsd#shc_PreIPOB2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ClassOfStockDomain_231672bf-52ad-4bbe-9eab-8f7ccfe36574" xlink:to="loc_shc_PreIPOB2Member_1dcb03d5-bb0a-4ad2-806e-7177226b132e" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/ShareBasedCompensationScheduleofStockOptionActivityDetails" xlink:type="simple" xlink:href="shc-20230331.xsd#ShareBasedCompensationScheduleofStockOptionActivityDetails"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/ShareBasedCompensationScheduleofStockOptionActivityDetails" xlink:type="extended" id="icbc122e5d9ba4a45bd46035bc6b62382_ShareBasedCompensationScheduleofStockOptionActivityDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f3b744f5-f324-42f5-a33d-a8803ad85202" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_6d5edc7b-ba7b-41a6-bb1d-370d2c963b51" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f3b744f5-f324-42f5-a33d-a8803ad85202" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_6d5edc7b-ba7b-41a6-bb1d-370d2c963b51" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_5f02390e-03c3-4042-9d5b-3d79a52cb54f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_6d5edc7b-ba7b-41a6-bb1d-370d2c963b51" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_5f02390e-03c3-4042-9d5b-3d79a52cb54f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_5ad27d90-df6f-485e-b1b1-54bf503652ee" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_6d5edc7b-ba7b-41a6-bb1d-370d2c963b51" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_5ad27d90-df6f-485e-b1b1-54bf503652ee" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares_cce3f3ff-e509-430d-9e5f-bb74927fd6fa" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_6d5edc7b-ba7b-41a6-bb1d-370d2c963b51" xlink:to="loc_us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares_cce3f3ff-e509-430d-9e5f-bb74927fd6fa" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_9e697ae3-6dfb-4a4b-8ad4-0491ec165472" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingRollForward_6d5edc7b-ba7b-41a6-bb1d-370d2c963b51" xlink:to="loc_us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_9e697ae3-6dfb-4a4b-8ad4-0491ec165472" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_3d3af533-bd4e-4bf6-a263-24eee0a027a6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_4e7fe46d-fe07-4c50-90bd-372fdb3e651d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f3b744f5-f324-42f5-a33d-a8803ad85202" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_4e7fe46d-fe07-4c50-90bd-372fdb3e651d" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_7a62c19b-f21d-45b4-ba38-152b507b7c5f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_4e7fe46d-fe07-4c50-90bd-372fdb3e651d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_7a62c19b-f21d-45b4-ba38-152b507b7c5f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_b27c6cc8-2f7c-4359-a9a9-7bc9b047379b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_4e7fe46d-fe07-4c50-90bd-372fdb3e651d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsGrantsInPeriodWeightedAverageExercisePrice_b27c6cc8-2f7c-4359-a9a9-7bc9b047379b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice_df7c3b1b-9f44-4160-8640-94de328facae" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_4e7fe46d-fe07-4c50-90bd-372fdb3e651d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsForfeituresInPeriodWeightedAverageExercisePrice_df7c3b1b-9f44-4160-8640-94de328facae" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_1b377e26-0de6-4d48-97c7-64924a4acaf5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceRollforward_4e7fe46d-fe07-4c50-90bd-372fdb3e651d" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_1b377e26-0de6-4d48-97c7-64924a4acaf5" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_80aa4e9a-0edf-4272-b93a-1c304606e98e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_3c8ee623-71f7-4ba5-b8fa-45e73d9bc264" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_f3b744f5-f324-42f5-a33d-a8803ad85202" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_3c8ee623-71f7-4ba5-b8fa-45e73d9bc264" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_0c4f7c83-9e3d-43a7-985c-f949badd6c18" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_3c8ee623-71f7-4ba5-b8fa-45e73d9bc264" xlink:to="loc_us-gaap_AwardTypeAxis_0c4f7c83-9e3d-43a7-985c-f949badd6c18" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0c4f7c83-9e3d-43a7-985c-f949badd6c18_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_0c4f7c83-9e3d-43a7-985c-f949badd6c18" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0c4f7c83-9e3d-43a7-985c-f949badd6c18_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_723f79db-c7a9-4539-aa66-063720219167" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_0c4f7c83-9e3d-43a7-985c-f949badd6c18" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_723f79db-c7a9-4539-aa66-063720219167" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_1d6b8d7a-6238-4518-99a9-98b16fe7a61d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_723f79db-c7a9-4539-aa66-063720219167" xlink:to="loc_us-gaap_EmployeeStockOptionMember_1d6b8d7a-6238-4518-99a9-98b16fe7a61d" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/ShareBasedCompensationScheduleofRestrictedStockActivityDetails" xlink:type="simple" xlink:href="shc-20230331.xsd#ShareBasedCompensationScheduleofRestrictedStockActivityDetails"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/ShareBasedCompensationScheduleofRestrictedStockActivityDetails" xlink:type="extended" id="ie888d18d36a64766b79a802ee3021a6f_ShareBasedCompensationScheduleofRestrictedStockActivityDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_bdf9d8fa-aaca-4e9d-822b-b8e530c4fda8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_602a0f32-ad56-4b22-ad2d-f521d04f5f9c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_bdf9d8fa-aaca-4e9d-822b-b8e530c4fda8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_602a0f32-ad56-4b22-ad2d-f521d04f5f9c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_a726d6ff-b2a3-4830-9886-3ce997ee9429" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_602a0f32-ad56-4b22-ad2d-f521d04f5f9c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_a726d6ff-b2a3-4830-9886-3ce997ee9429" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_1c5c9ea0-16dc-4217-be39-3e69d0f7ca3b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_602a0f32-ad56-4b22-ad2d-f521d04f5f9c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_1c5c9ea0-16dc-4217-be39-3e69d0f7ca3b" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_f0862a85-62b3-4cae-995e-01fb4cf595a1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_602a0f32-ad56-4b22-ad2d-f521d04f5f9c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_f0862a85-62b3-4cae-995e-01fb4cf595a1" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_c270eddd-aeab-4fde-8c70-9b5d3ee74d4e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedRollForward_602a0f32-ad56-4b22-ad2d-f521d04f5f9c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_c270eddd-aeab-4fde-8c70-9b5d3ee74d4e" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_ccc1d47a-5199-403b-a35a-100852e5cf02" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_e9e12e28-267d-425a-a657-23d0a9854b6c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_bdf9d8fa-aaca-4e9d-822b-b8e530c4fda8" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_e9e12e28-267d-425a-a657-23d0a9854b6c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_e9e4fde4-0c8a-45a8-aeff-fe0c5ed4b835" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_e9e12e28-267d-425a-a657-23d0a9854b6c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_e9e4fde4-0c8a-45a8-aeff-fe0c5ed4b835" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_d4eec9e4-68a4-4217-9689-8b34b8b76dda" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_e9e12e28-267d-425a-a657-23d0a9854b6c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriodWeightedAverageGrantDateFairValue_d4eec9e4-68a4-4217-9689-8b34b8b76dda" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_f201537f-3655-4856-b071-b033c4b6fd3f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_e9e12e28-267d-425a-a657-23d0a9854b6c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeituresWeightedAverageGrantDateFairValue_f201537f-3655-4856-b071-b033c4b6fd3f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_a6475e41-65f7-4bbe-b5db-8bf7d447fbfa" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValueRollForward_e9e12e28-267d-425a-a657-23d0a9854b6c" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriodWeightedAverageGrantDateFairValue_a6475e41-65f7-4bbe-b5db-8bf7d447fbfa" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue_25b1f588-cd8e-4203-bdf4-cd6303f30375" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedWeightedAverageGrantDateFairValue"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_5d730443-d748-4cdc-87ba-0e29a56707c1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_bdf9d8fa-aaca-4e9d-822b-b8e530c4fda8" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_5d730443-d748-4cdc-87ba-0e29a56707c1" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_badb9f71-0e43-4e64-8627-d6d32d9937fc" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_5d730443-d748-4cdc-87ba-0e29a56707c1" xlink:to="loc_us-gaap_AwardTypeAxis_badb9f71-0e43-4e64-8627-d6d32d9937fc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_badb9f71-0e43-4e64-8627-d6d32d9937fc_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_badb9f71-0e43-4e64-8627-d6d32d9937fc" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_badb9f71-0e43-4e64-8627-d6d32d9937fc_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_adfc4e95-d55e-4f16-bd8d-3652b6cfba76" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_badb9f71-0e43-4e64-8627-d6d32d9937fc" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_adfc4e95-d55e-4f16-bd8d-3652b6cfba76" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_5a256dcf-37c5-450e-802d-57c71f7bd87f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_adfc4e95-d55e-4f16-bd8d-3652b6cfba76" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_5a256dcf-37c5-450e-802d-57c71f7bd87f" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/EarningsPerShareDetails" xlink:type="simple" xlink:href="shc-20230331.xsd#EarningsPerShareDetails"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/EarningsPerShareDetails" xlink:type="extended" id="i1c24253e9bca4374bf6f81a75b7a1609_EarningsPerShareDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_5e93cc39-0d85-49f7-9edc-c2fa4a10dc08" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_ac336f9a-44fb-4240-ac8d-a40e9ab8eac1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_5e93cc39-0d85-49f7-9edc-c2fa4a10dc08" xlink:to="loc_us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareAmount_ac336f9a-44fb-4240-ac8d-a40e9ab8eac1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4fb118be-e9bb-4abd-9ba1-1e1de13728bc" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_5e93cc39-0d85-49f7-9edc-c2fa4a10dc08" xlink:to="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4fb118be-e9bb-4abd-9ba1-1e1de13728bc" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AwardTypeAxis_0b3d401e-ec4e-4fe0-8066-3963c2102198" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AwardTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_4fb118be-e9bb-4abd-9ba1-1e1de13728bc" xlink:to="loc_us-gaap_AwardTypeAxis_0b3d401e-ec4e-4fe0-8066-3963c2102198" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0b3d401e-ec4e-4fe0-8066-3963c2102198_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_AwardTypeAxis_0b3d401e-ec4e-4fe0-8066-3963c2102198" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0b3d401e-ec4e-4fe0-8066-3963c2102198_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0eb808fb-66bf-44cf-a5aa-ade72e86f48c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_AwardTypeAxis_0b3d401e-ec4e-4fe0-8066-3963c2102198" xlink:to="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0eb808fb-66bf-44cf-a5aa-ade72e86f48c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmployeeStockOptionMember_bd6e5882-2a72-400c-98ff-703947552eab" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EmployeeStockOptionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0eb808fb-66bf-44cf-a5aa-ade72e86f48c" xlink:to="loc_us-gaap_EmployeeStockOptionMember_bd6e5882-2a72-400c-98ff-703947552eab" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RestrictedStockUnitsRSUMember_89d98766-9aeb-4c92-b671-56e35ceaab29" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RestrictedStockUnitsRSUMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_0eb808fb-66bf-44cf-a5aa-ade72e86f48c" xlink:to="loc_us-gaap_RestrictedStockUnitsRSUMember_89d98766-9aeb-4c92-b671-56e35ceaab29" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/CommitmentsandContingenciesDetails" xlink:type="simple" xlink:href="shc-20230331.xsd#CommitmentsandContingenciesDetails"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/CommitmentsandContingenciesDetails" xlink:type="extended" id="i332c8fd5592d4473822d19cf2b4a7e86_CommitmentsandContingenciesDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainContingenciesLineItems_51cbd653-20a0-48db-b30f-d215ac9cf836" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GainContingenciesLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNumberOfPlaintiffs_a6684489-0cbf-4314-a828-160bb2d1a799" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LossContingencyNumberOfPlaintiffs"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GainContingenciesLineItems_51cbd653-20a0-48db-b30f-d215ac9cf836" xlink:to="loc_us-gaap_LossContingencyNumberOfPlaintiffs_a6684489-0cbf-4314-a828-160bb2d1a799" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_LossContingencyNumberOfIndividualsThreatenedToFileLawsuits_e57ce146-64c4-4aad-a7a7-a3c76a2f61ab" xlink:href="shc-20230331.xsd#shc_LossContingencyNumberOfIndividualsThreatenedToFileLawsuits"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GainContingenciesLineItems_51cbd653-20a0-48db-b30f-d215ac9cf836" xlink:to="loc_shc_LossContingencyNumberOfIndividualsThreatenedToFileLawsuits_e57ce146-64c4-4aad-a7a7-a3c76a2f61ab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_LossContingencyConsolidatedClaimsNumber_d5adf02d-8a57-4d37-8708-caccf21f29f2" xlink:href="shc-20230331.xsd#shc_LossContingencyConsolidatedClaimsNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GainContingenciesLineItems_51cbd653-20a0-48db-b30f-d215ac9cf836" xlink:to="loc_shc_LossContingencyConsolidatedClaimsNumber_d5adf02d-8a57-4d37-8708-caccf21f29f2" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_LossContingencyClaimsScheduledForTrialsNumber_3ca353b1-c949-4568-aa4d-4ddf84210b1a" xlink:href="shc-20230331.xsd#shc_LossContingencyClaimsScheduledForTrialsNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GainContingenciesLineItems_51cbd653-20a0-48db-b30f-d215ac9cf836" xlink:to="loc_shc_LossContingencyClaimsScheduledForTrialsNumber_3ca353b1-c949-4568-aa4d-4ddf84210b1a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationSettlementAmountAwardedToOtherParty_929a8bc4-fa05-4b60-9e2a-83ff98602453" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LitigationSettlementAmountAwardedToOtherParty"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GainContingenciesLineItems_51cbd653-20a0-48db-b30f-d215ac9cf836" xlink:to="loc_us-gaap_LitigationSettlementAmountAwardedToOtherParty_929a8bc4-fa05-4b60-9e2a-83ff98602453" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNewClaimsFiledNumber_67d15177-08c3-4352-b0e5-7cdd2e79b20e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LossContingencyNewClaimsFiledNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GainContingenciesLineItems_51cbd653-20a0-48db-b30f-d215ac9cf836" xlink:to="loc_us-gaap_LossContingencyNewClaimsFiledNumber_67d15177-08c3-4352-b0e5-7cdd2e79b20e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_EligibleClaimantsPercentage_c460291a-02e7-4e43-a3d4-10b43e2d34e3" xlink:href="shc-20230331.xsd#shc_EligibleClaimantsPercentage"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GainContingenciesLineItems_51cbd653-20a0-48db-b30f-d215ac9cf836" xlink:to="loc_shc_EligibleClaimantsPercentage_c460291a-02e7-4e43-a3d4-10b43e2d34e3" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_NumberOfDaysToClaimantReceivesAllDisclosureMinimum_19462363-de94-41f0-8d1d-8fe389a11e3f" xlink:href="shc-20230331.xsd#shc_NumberOfDaysToClaimantReceivesAllDisclosureMinimum"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GainContingenciesLineItems_51cbd653-20a0-48db-b30f-d215ac9cf836" xlink:to="loc_shc_NumberOfDaysToClaimantReceivesAllDisclosureMinimum_19462363-de94-41f0-8d1d-8fe389a11e3f" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyEstimateOfPossibleLoss_023ba786-202a-4727-88c9-ecf512fc48ae" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LossContingencyEstimateOfPossibleLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GainContingenciesLineItems_51cbd653-20a0-48db-b30f-d215ac9cf836" xlink:to="loc_us-gaap_LossContingencyEstimateOfPossibleLoss_023ba786-202a-4727-88c9-ecf512fc48ae" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentFaceAmount_7ead8fb7-0d33-42da-bc43-c4fd912cc2a0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentFaceAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GainContingenciesLineItems_51cbd653-20a0-48db-b30f-d215ac9cf836" xlink:to="loc_us-gaap_DebtInstrumentFaceAmount_7ead8fb7-0d33-42da-bc43-c4fd912cc2a0" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_NumberOfConsolidatedCases_5d6cdf16-ca48-4d37-a120-6198b0c0e814" xlink:href="shc-20230331.xsd#shc_NumberOfConsolidatedCases"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GainContingenciesLineItems_51cbd653-20a0-48db-b30f-d215ac9cf836" xlink:to="loc_shc_NumberOfConsolidatedCases_5d6cdf16-ca48-4d37-a120-6198b0c0e814" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_LossContingencyUndiscountedAmountOfInsuranceRelatedAssessmentLiabilityPerOccurrence_2fd0b8b7-c010-4544-8509-b28479fd11cf" xlink:href="shc-20230331.xsd#shc_LossContingencyUndiscountedAmountOfInsuranceRelatedAssessmentLiabilityPerOccurrence"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GainContingenciesLineItems_51cbd653-20a0-48db-b30f-d215ac9cf836" xlink:to="loc_shc_LossContingencyUndiscountedAmountOfInsuranceRelatedAssessmentLiabilityPerOccurrence_2fd0b8b7-c010-4544-8509-b28479fd11cf" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyUndiscountedAmountOfInsuranceRelatedAssessmentLiability_66fb97eb-9e29-4471-9112-bf3b0e2f17c7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LossContingencyUndiscountedAmountOfInsuranceRelatedAssessmentLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_GainContingenciesLineItems_51cbd653-20a0-48db-b30f-d215ac9cf836" xlink:to="loc_us-gaap_LossContingencyUndiscountedAmountOfInsuranceRelatedAssessmentLiability_66fb97eb-9e29-4471-9112-bf3b0e2f17c7" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainContingenciesTable_c7a32fc8-429d-4f04-9702-60c0c2344a25" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GainContingenciesTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_GainContingenciesLineItems_51cbd653-20a0-48db-b30f-d215ac9cf836" xlink:to="loc_us-gaap_GainContingenciesTable_c7a32fc8-429d-4f04-9702-60c0c2344a25" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseAxis_a2f311b3-9de3-4286-ac68-bb11889d1386" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_LitigationCaseAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_GainContingenciesTable_c7a32fc8-429d-4f04-9702-60c0c2344a25" xlink:to="loc_srt_LitigationCaseAxis_a2f311b3-9de3-4286-ac68-bb11889d1386" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseTypeDomain_a2f311b3-9de3-4286-ac68-bb11889d1386_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_LitigationCaseTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_LitigationCaseAxis_a2f311b3-9de3-4286-ac68-bb11889d1386" xlink:to="loc_srt_LitigationCaseTypeDomain_a2f311b3-9de3-4286-ac68-bb11889d1386_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseTypeDomain_a257fbd4-03d2-49ce-9d51-df8344a01d30" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_LitigationCaseTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_LitigationCaseAxis_a2f311b3-9de3-4286-ac68-bb11889d1386" xlink:to="loc_srt_LitigationCaseTypeDomain_a257fbd4-03d2-49ce-9d51-df8344a01d30" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_EthyleneOxideTortLitigationIllinoisMember_2cfbee45-72f8-425a-9574-3ff9768e13b2" xlink:href="shc-20230331.xsd#shc_EthyleneOxideTortLitigationIllinoisMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_a257fbd4-03d2-49ce-9d51-df8344a01d30" xlink:to="loc_shc_EthyleneOxideTortLitigationIllinoisMember_2cfbee45-72f8-425a-9574-3ff9768e13b2" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_AssetTransferCaseMemberMember_267ce93e-5258-4394-8a34-3ea205dcb95b" xlink:href="shc-20230331.xsd#shc_AssetTransferCaseMemberMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_a257fbd4-03d2-49ce-9d51-df8344a01d30" xlink:to="loc_shc_AssetTransferCaseMemberMember_267ce93e-5258-4394-8a34-3ea205dcb95b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_EthyleneOxideTortLitigationGeorgiaMember_ca5abb43-e40f-4cf5-be0e-177b4426c2bb" xlink:href="shc-20230331.xsd#shc_EthyleneOxideTortLitigationGeorgiaMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_a257fbd4-03d2-49ce-9d51-df8344a01d30" xlink:to="loc_shc_EthyleneOxideTortLitigationGeorgiaMember_ca5abb43-e40f-4cf5-be0e-177b4426c2bb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_e13eb207-8c4e-425e-a0f2-8119d8e032bb" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_GainContingenciesTable_c7a32fc8-429d-4f04-9702-60c0c2344a25" xlink:to="loc_srt_RangeAxis_e13eb207-8c4e-425e-a0f2-8119d8e032bb" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_e13eb207-8c4e-425e-a0f2-8119d8e032bb_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_e13eb207-8c4e-425e-a0f2-8119d8e032bb" xlink:to="loc_srt_RangeMember_e13eb207-8c4e-425e-a0f2-8119d8e032bb_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_63f52849-78c8-47d9-bb3b-1d1c9f6cfaab" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_e13eb207-8c4e-425e-a0f2-8119d8e032bb" xlink:to="loc_srt_RangeMember_63f52849-78c8-47d9-bb3b-1d1c9f6cfaab" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_dfaa891a-fcab-4fe3-819a-c290127b391b" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_63f52849-78c8-47d9-bb3b-1d1c9f6cfaab" xlink:to="loc_srt_MinimumMember_dfaa891a-fcab-4fe3-819a-c290127b391b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusAxis_1e2b8797-a81d-468c-bc1c-7fde4ecddd52" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LitigationStatusAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_GainContingenciesTable_c7a32fc8-429d-4f04-9702-60c0c2344a25" xlink:to="loc_us-gaap_LitigationStatusAxis_1e2b8797-a81d-468c-bc1c-7fde4ecddd52" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusDomain_1e2b8797-a81d-468c-bc1c-7fde4ecddd52_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LitigationStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LitigationStatusAxis_1e2b8797-a81d-468c-bc1c-7fde4ecddd52" xlink:to="loc_us-gaap_LitigationStatusDomain_1e2b8797-a81d-468c-bc1c-7fde4ecddd52_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusDomain_deb336f3-5720-4af5-84c7-8f8cb61cabe6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LitigationStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LitigationStatusAxis_1e2b8797-a81d-468c-bc1c-7fde4ecddd52" xlink:to="loc_us-gaap_LitigationStatusDomain_deb336f3-5720-4af5-84c7-8f8cb61cabe6" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PendingLitigationMember_3b4ed082-2d68-44f1-afec-d56138767f90" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PendingLitigationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LitigationStatusDomain_deb336f3-5720-4af5-84c7-8f8cb61cabe6" xlink:to="loc_us-gaap_PendingLitigationMember_3b4ed082-2d68-44f1-afec-d56138767f90" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesAxis_66408adf-8515-439a-89c3-02e9a03e16aa" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidatedEntitiesAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_GainContingenciesTable_c7a32fc8-429d-4f04-9702-60c0c2344a25" xlink:to="loc_srt_ConsolidatedEntitiesAxis_66408adf-8515-439a-89c3-02e9a03e16aa" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_66408adf-8515-439a-89c3-02e9a03e16aa_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidatedEntitiesAxis_66408adf-8515-439a-89c3-02e9a03e16aa" xlink:to="loc_srt_ConsolidatedEntitiesDomain_66408adf-8515-439a-89c3-02e9a03e16aa_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidatedEntitiesDomain_dcf427a0-60cf-43ca-b99a-5c23c710e69a" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidatedEntitiesDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidatedEntitiesAxis_66408adf-8515-439a-89c3-02e9a03e16aa" xlink:to="loc_srt_ConsolidatedEntitiesDomain_dcf427a0-60cf-43ca-b99a-5c23c710e69a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SubsidiariesMember_a95e3ca5-8c38-45ff-b67c-c0384b28adce" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_SubsidiariesMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidatedEntitiesDomain_dcf427a0-60cf-43ca-b99a-5c23c710e69a" xlink:to="loc_srt_SubsidiariesMember_a95e3ca5-8c38-45ff-b67c-c0384b28adce" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeAxis_28979212-7a54-4ab0-ba5c-4506a987f72c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_GainContingenciesTable_c7a32fc8-429d-4f04-9702-60c0c2344a25" xlink:to="loc_us-gaap_SubsequentEventTypeAxis_28979212-7a54-4ab0-ba5c-4506a987f72c" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_28979212-7a54-4ab0-ba5c-4506a987f72c_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_28979212-7a54-4ab0-ba5c-4506a987f72c" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_28979212-7a54-4ab0-ba5c-4506a987f72c_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventTypeDomain_af62eba9-0eb8-478d-bc39-8dbdbddfc3a0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_SubsequentEventTypeAxis_28979212-7a54-4ab0-ba5c-4506a987f72c" xlink:to="loc_us-gaap_SubsequentEventTypeDomain_af62eba9-0eb8-478d-bc39-8dbdbddfc3a0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SubsequentEventMember_af8db14e-35c5-4b7e-808f-1c87c2a6666b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SubsequentEventMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SubsequentEventTypeDomain_af62eba9-0eb8-478d-bc39-8dbdbddfc3a0" xlink:to="loc_us-gaap_SubsequentEventMember_af8db14e-35c5-4b7e-808f-1c87c2a6666b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_StatementGeographicalAxis_556e5d04-8129-47ab-8ab7-632507c92816" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_StatementGeographicalAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_GainContingenciesTable_c7a32fc8-429d-4f04-9702-60c0c2344a25" xlink:to="loc_srt_StatementGeographicalAxis_556e5d04-8129-47ab-8ab7-632507c92816" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_556e5d04-8129-47ab-8ab7-632507c92816_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_StatementGeographicalAxis_556e5d04-8129-47ab-8ab7-632507c92816" xlink:to="loc_srt_SegmentGeographicalDomain_556e5d04-8129-47ab-8ab7-632507c92816_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_SegmentGeographicalDomain_6d066b5c-b033-4523-85d9-20311e932c8c" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_SegmentGeographicalDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_StatementGeographicalAxis_556e5d04-8129-47ab-8ab7-632507c92816" xlink:to="loc_srt_SegmentGeographicalDomain_6d066b5c-b033-4523-85d9-20311e932c8c" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_GwinnettCountyMember_a0ae2362-6f42-41cb-b1ca-d90c7d0c36e3" xlink:href="shc-20230331.xsd#shc_GwinnettCountyMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_SegmentGeographicalDomain_6d066b5c-b033-4523-85d9-20311e932c8c" xlink:to="loc_shc_GwinnettCountyMember_a0ae2362-6f42-41cb-b1ca-d90c7d0c36e3" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_f2bd1b44-31ee-43c9-921c-d7e4449dad11" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LossContingenciesByNatureOfContingencyAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_GainContingenciesTable_c7a32fc8-429d-4f04-9702-60c0c2344a25" xlink:to="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_f2bd1b44-31ee-43c9-921c-d7e4449dad11" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_f2bd1b44-31ee-43c9-921c-d7e4449dad11_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_f2bd1b44-31ee-43c9-921c-d7e4449dad11" xlink:to="loc_us-gaap_LossContingencyNatureDomain_f2bd1b44-31ee-43c9-921c-d7e4449dad11_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyNatureDomain_319c688c-37b5-4fde-bf7e-a27f94fb9e74" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LossContingencyNatureDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LossContingenciesByNatureOfContingencyAxis_f2bd1b44-31ee-43c9-921c-d7e4449dad11" xlink:to="loc_us-gaap_LossContingencyNatureDomain_319c688c-37b5-4fde-bf7e-a27f94fb9e74" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_CompensatoryDamagesMemberMember_38c8a2bf-ee5c-4084-af8a-65c7e8377512" xlink:href="shc-20230331.xsd#shc_CompensatoryDamagesMemberMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_319c688c-37b5-4fde-bf7e-a27f94fb9e74" xlink:to="loc_shc_CompensatoryDamagesMemberMember_38c8a2bf-ee5c-4084-af8a-65c7e8377512" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_PunitiveDamagesMemberMember_54aa8eb7-d077-4401-8116-f4605b135ae9" xlink:href="shc-20230331.xsd#shc_PunitiveDamagesMemberMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_319c688c-37b5-4fde-bf7e-a27f94fb9e74" xlink:to="loc_shc_PunitiveDamagesMemberMember_54aa8eb7-d077-4401-8116-f4605b135ae9" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_RealEstateDamageMember_680cdb44-bc6c-4d07-ab01-3a4961df874e" xlink:href="shc-20230331.xsd#shc_RealEstateDamageMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_319c688c-37b5-4fde-bf7e-a27f94fb9e74" xlink:to="loc_shc_RealEstateDamageMember_680cdb44-bc6c-4d07-ab01-3a4961df874e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_InjuryMember_a7828658-f92f-4735-9ccb-0f131790ffbb" xlink:href="shc-20230331.xsd#shc_InjuryMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LossContingencyNatureDomain_319c688c-37b5-4fde-bf7e-a27f94fb9e74" xlink:to="loc_shc_InjuryMember_a7828658-f92f-4735-9ccb-0f131790ffbb" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_LegalEntityAxis_3461e30d-9acf-4a97-8f02-57192cda9416" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_LegalEntityAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_GainContingenciesTable_c7a32fc8-429d-4f04-9702-60c0c2344a25" xlink:to="loc_dei_LegalEntityAxis_3461e30d-9acf-4a97-8f02-57192cda9416" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_3461e30d-9acf-4a97-8f02-57192cda9416_default" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_dei_LegalEntityAxis_3461e30d-9acf-4a97-8f02-57192cda9416" xlink:to="loc_dei_EntityDomain_3461e30d-9acf-4a97-8f02-57192cda9416_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_dei_EntityDomain_0a7bdea9-3076-42cd-a907-1bf4ab5d9649" xlink:href="https://xbrl.sec.gov/dei/2022/dei-2022.xsd#dei_EntityDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_dei_LegalEntityAxis_3461e30d-9acf-4a97-8f02-57192cda9416" xlink:to="loc_dei_EntityDomain_0a7bdea9-3076-42cd-a907-1bf4ab5d9649" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_CoDefendantMemberMember_e7e81e4e-42af-4fea-b4e1-d77184b0e767" xlink:href="shc-20230331.xsd#shc_CoDefendantMemberMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_0a7bdea9-3076-42cd-a907-1bf4ab5d9649" xlink:to="loc_shc_CoDefendantMemberMember_e7e81e4e-42af-4fea-b4e1-d77184b0e767" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_PECMemberMember_38c8677b-ad9f-4b37-9f89-37afad93e455" xlink:href="shc-20230331.xsd#shc_PECMemberMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_dei_EntityDomain_0a7bdea9-3076-42cd-a907-1bf4ab5d9649" xlink:to="loc_shc_PECMemberMember_38c8677b-ad9f-4b37-9f89-37afad93e455" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeAxis_a6356805-3d5e-431e-893f-4762f9d2c0e4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_GainContingenciesTable_c7a32fc8-429d-4f04-9702-60c0c2344a25" xlink:to="loc_us-gaap_LongtermDebtTypeAxis_a6356805-3d5e-431e-893f-4762f9d2c0e4" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_a6356805-3d5e-431e-893f-4762f9d2c0e4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_a6356805-3d5e-431e-893f-4762f9d2c0e4" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_a6356805-3d5e-431e-893f-4762f9d2c0e4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongtermDebtTypeDomain_02e3fec4-3c2e-49b0-993f-d53e87cf6c0e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongtermDebtTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LongtermDebtTypeAxis_a6356805-3d5e-431e-893f-4762f9d2c0e4" xlink:to="loc_us-gaap_LongtermDebtTypeDomain_02e3fec4-3c2e-49b0-993f-d53e87cf6c0e" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredDebtMember_4ebded09-7563-4b98-8579-5a37d3608184" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SecuredDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LongtermDebtTypeDomain_02e3fec4-3c2e-49b0-993f-d53e87cf6c0e" xlink:to="loc_us-gaap_SecuredDebtMember_4ebded09-7563-4b98-8579-5a37d3608184" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_57e2b75a-806f-4c23-8c4e-68db8a5abbea" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_GainContingenciesTable_c7a32fc8-429d-4f04-9702-60c0c2344a25" xlink:to="loc_us-gaap_DebtInstrumentAxis_57e2b75a-806f-4c23-8c4e-68db8a5abbea" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_57e2b75a-806f-4c23-8c4e-68db8a5abbea_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_57e2b75a-806f-4c23-8c4e-68db8a5abbea" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_57e2b75a-806f-4c23-8c4e-68db8a5abbea_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_64ef25c6-fb87-40f3-ac7e-ea60c5c95358" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_57e2b75a-806f-4c23-8c4e-68db8a5abbea" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_64ef25c6-fb87-40f3-ac7e-ea60c5c95358" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_FirstLienNotesDue2026Member_104849b1-b528-464e-9790-56dafee14ae0" xlink:href="shc-20230331.xsd#shc_FirstLienNotesDue2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_64ef25c6-fb87-40f3-ac7e-ea60c5c95358" xlink:to="loc_shc_FirstLienNotesDue2026Member_104849b1-b528-464e-9790-56dafee14ae0" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/FinancialInstrumentsandFinancialRiskNarrativeDetails" xlink:type="simple" xlink:href="shc-20230331.xsd#FinancialInstrumentsandFinancialRiskNarrativeDetails"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/FinancialInstrumentsandFinancialRiskNarrativeDetails" xlink:type="extended" id="iecd11cf129da41c9878ed95d555c5b3e_FinancialInstrumentsandFinancialRiskNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_8d3213cd-465c-439a-a0fa-36f11db2270a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_83256e7e-f107-4c05-ad1f-a15012ff5074" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_8d3213cd-465c-439a-a0fa-36f11db2270a" xlink:to="loc_us-gaap_DerivativeNotionalAmount_83256e7e-f107-4c05-ad1f-a15012ff5074" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNumberOfInstrumentsHeld_55e9e96f-9463-46cb-99e4-59d58a858e85" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeNumberOfInstrumentsHeld"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_8d3213cd-465c-439a-a0fa-36f11db2270a" xlink:to="loc_us-gaap_DerivativeNumberOfInstrumentsHeld_55e9e96f-9463-46cb-99e4-59d58a858e85" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_DerivativeOptionPremium_93291ac5-ca2c-4895-bc82-17caf456267f" xlink:href="shc-20230331.xsd#shc_DerivativeOptionPremium"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_8d3213cd-465c-439a-a0fa-36f11db2270a" xlink:to="loc_shc_DerivativeOptionPremium_93291ac5-ca2c-4895-bc82-17caf456267f" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_PercentOfBorrowingLimitationDueToCashFlowExposure_33e48db6-93d1-42e3-b620-ae50d708f27a" xlink:href="shc-20230331.xsd#shc_PercentOfBorrowingLimitationDueToCashFlowExposure"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_8d3213cd-465c-439a-a0fa-36f11db2270a" xlink:to="loc_shc_PercentOfBorrowingLimitationDueToCashFlowExposure_33e48db6-93d1-42e3-b620-ae50d708f27a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax_ca3a3091-af95-4ed7-a26c-338713001993" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_8d3213cd-465c-439a-a0fa-36f11db2270a" xlink:to="loc_us-gaap_OtherComprehensiveIncomeLossCashFlowHedgeGainLossAfterReclassificationAndTax_ca3a3091-af95-4ed7-a26c-338713001993" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_b9c727ef-19de-46fb-a809-4a08e2b99c20" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_8d3213cd-465c-439a-a0fa-36f11db2270a" xlink:to="loc_us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_b9c727ef-19de-46fb-a809-4a08e2b99c20" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_50f5762f-1163-4e27-be67-e6c71d7ddf49" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_8d3213cd-465c-439a-a0fa-36f11db2270a" xlink:to="loc_us-gaap_DerivativeTable_50f5762f-1163-4e27-be67-e6c71d7ddf49" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_8e6689ba-fce6-4635-a65a-a59b341315c1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_50f5762f-1163-4e27-be67-e6c71d7ddf49" xlink:to="loc_us-gaap_HedgingDesignationAxis_8e6689ba-fce6-4635-a65a-a59b341315c1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_8e6689ba-fce6-4635-a65a-a59b341315c1_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_8e6689ba-fce6-4635-a65a-a59b341315c1" xlink:to="loc_us-gaap_HedgingDesignationDomain_8e6689ba-fce6-4635-a65a-a59b341315c1_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_41285dca-124d-433e-b398-6ba64385d370" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_8e6689ba-fce6-4635-a65a-a59b341315c1" xlink:to="loc_us-gaap_HedgingDesignationDomain_41285dca-124d-433e-b398-6ba64385d370" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_91063d99-3806-4fdf-bcb2-468423c87789" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_41285dca-124d-433e-b398-6ba64385d370" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_91063d99-3806-4fdf-bcb2-468423c87789" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NondesignatedMember_de4f46db-7a68-4aca-b2ec-260631dfc5e8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NondesignatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_41285dca-124d-433e-b398-6ba64385d370" xlink:to="loc_us-gaap_NondesignatedMember_de4f46db-7a68-4aca-b2ec-260631dfc5e8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_fe17846e-aa6c-4a92-a482-3a0f2cb3d5b4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_50f5762f-1163-4e27-be67-e6c71d7ddf49" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_fe17846e-aa6c-4a92-a482-3a0f2cb3d5b4" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_fe17846e-aa6c-4a92-a482-3a0f2cb3d5b4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_fe17846e-aa6c-4a92-a482-3a0f2cb3d5b4" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_fe17846e-aa6c-4a92-a482-3a0f2cb3d5b4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_7ac21e7e-5bf0-4433-b85f-5f96b8e1dd71" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_fe17846e-aa6c-4a92-a482-3a0f2cb3d5b4" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_7ac21e7e-5bf0-4433-b85f-5f96b8e1dd71" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_2dd872a2-1570-4798-9311-e185e7f45384" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_7ac21e7e-5bf0-4433-b85f-5f96b8e1dd71" xlink:to="loc_us-gaap_InterestRateSwapMember_2dd872a2-1570-4798-9311-e185e7f45384" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateCapMember_59ad5074-6aa1-43d4-a1ca-2318736a31ad" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestRateCapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_7ac21e7e-5bf0-4433-b85f-5f96b8e1dd71" xlink:to="loc_us-gaap_InterestRateCapMember_59ad5074-6aa1-43d4-a1ca-2318736a31ad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_e7fd3573-1cb1-4ec7-b380-d0a78f52e9c3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_7ac21e7e-5bf0-4433-b85f-5f96b8e1dd71" xlink:to="loc_us-gaap_ForeignExchangeContractMember_e7fd3573-1cb1-4ec7-b380-d0a78f52e9c3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateAxis_f1d081ca-cf6f-4670-b894-b5da7da11b63" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VariableRateAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_50f5762f-1163-4e27-be67-e6c71d7ddf49" xlink:to="loc_us-gaap_VariableRateAxis_f1d081ca-cf6f-4670-b894-b5da7da11b63" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_f1d081ca-cf6f-4670-b894-b5da7da11b63_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_VariableRateAxis_f1d081ca-cf6f-4670-b894-b5da7da11b63" xlink:to="loc_us-gaap_VariableRateDomain_f1d081ca-cf6f-4670-b894-b5da7da11b63_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_VariableRateDomain_1402333c-eb02-41ac-9127-9afed3cdd47b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_VariableRateDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_VariableRateAxis_f1d081ca-cf6f-4670-b894-b5da7da11b63" xlink:to="loc_us-gaap_VariableRateDomain_1402333c-eb02-41ac-9127-9afed3cdd47b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember_8e8a9d6d-2831-4c66-9b57-80df154b6276" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_1402333c-eb02-41ac-9127-9afed3cdd47b" xlink:to="loc_us-gaap_SecuredOvernightFinancingRateSofrOvernightIndexSwapRateMember_8e8a9d6d-2831-4c66-9b57-80df154b6276" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_c888b2b2-079c-4d10-af6a-db0bc7d1a7eb" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LondonInterbankOfferedRateLIBORMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_VariableRateDomain_1402333c-eb02-41ac-9127-9afed3cdd47b" xlink:to="loc_us-gaap_LondonInterbankOfferedRateLIBORMember_c888b2b2-079c-4d10-af6a-db0bc7d1a7eb" xlink:type="arc" order="1"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/FinancialInstrumentsandFinancialRiskScheduleofDerivativeInstrumentsDetails" xlink:type="simple" xlink:href="shc-20230331.xsd#FinancialInstrumentsandFinancialRiskScheduleofDerivativeInstrumentsDetails"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/FinancialInstrumentsandFinancialRiskScheduleofDerivativeInstrumentsDetails" xlink:type="extended" id="i571b90e1cb7049a0afed71b593c9e6b5_FinancialInstrumentsandFinancialRiskScheduleofDerivativeInstrumentsDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_23c17550-0029-43e5-b3d6-4043c587a211" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeNotionalAmount_93b174b8-275b-4b44-a98f-6716ef22aa7c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeNotionalAmount"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_23c17550-0029-43e5-b3d6-4043c587a211" xlink:to="loc_us-gaap_DerivativeNotionalAmount_93b174b8-275b-4b44-a98f-6716ef22aa7c" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_c1e4aa7b-2a07-452c-9555-473e1623d9ad" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeFairValueOfDerivativeAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_23c17550-0029-43e5-b3d6-4043c587a211" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_c1e4aa7b-2a07-452c-9555-473e1623d9ad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_5ed536e6-cb5a-456a-9ed4-ed88f6e64b80" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeFairValueOfDerivativeLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_23c17550-0029-43e5-b3d6-4043c587a211" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_5ed536e6-cb5a-456a-9ed4-ed88f6e64b80" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_5c85202e-86e7-4704-b752-5017cd53b2b6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_23c17550-0029-43e5-b3d6-4043c587a211" xlink:to="loc_us-gaap_DerivativeTable_5c85202e-86e7-4704-b752-5017cd53b2b6" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_7418dca8-9a5d-4fc0-aa0b-5dab5dbde803" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_5c85202e-86e7-4704-b752-5017cd53b2b6" xlink:to="loc_us-gaap_HedgingDesignationAxis_7418dca8-9a5d-4fc0-aa0b-5dab5dbde803" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_7418dca8-9a5d-4fc0-aa0b-5dab5dbde803_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_7418dca8-9a5d-4fc0-aa0b-5dab5dbde803" xlink:to="loc_us-gaap_HedgingDesignationDomain_7418dca8-9a5d-4fc0-aa0b-5dab5dbde803_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_688c3556-66d3-42e8-b54a-a066d6dc7d83" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_7418dca8-9a5d-4fc0-aa0b-5dab5dbde803" xlink:to="loc_us-gaap_HedgingDesignationDomain_688c3556-66d3-42e8-b54a-a066d6dc7d83" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_cc5b125d-cd69-4f7f-9fb2-9c9cd1aa1786" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_688c3556-66d3-42e8-b54a-a066d6dc7d83" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_cc5b125d-cd69-4f7f-9fb2-9c9cd1aa1786" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NondesignatedMember_6b19a853-4c69-4391-8b83-c23f7ce446c5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NondesignatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_688c3556-66d3-42e8-b54a-a066d6dc7d83" xlink:to="loc_us-gaap_NondesignatedMember_6b19a853-4c69-4391-8b83-c23f7ce446c5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_867e37ad-54e4-49fa-ad2a-d9bdf67125d7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_5c85202e-86e7-4704-b752-5017cd53b2b6" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_867e37ad-54e4-49fa-ad2a-d9bdf67125d7" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_867e37ad-54e4-49fa-ad2a-d9bdf67125d7_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_867e37ad-54e4-49fa-ad2a-d9bdf67125d7" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_867e37ad-54e4-49fa-ad2a-d9bdf67125d7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_6ce0a861-cd6a-4722-aec6-1c24b6b71475" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_867e37ad-54e4-49fa-ad2a-d9bdf67125d7" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_6ce0a861-cd6a-4722-aec6-1c24b6b71475" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateCapMember_a5fddd02-04c7-4af1-a6ae-e64306fa1c7b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestRateCapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_6ce0a861-cd6a-4722-aec6-1c24b6b71475" xlink:to="loc_us-gaap_InterestRateCapMember_a5fddd02-04c7-4af1-a6ae-e64306fa1c7b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_d603cec6-aa51-469c-aece-5860dac6cd0f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_6ce0a861-cd6a-4722-aec6-1c24b6b71475" xlink:to="loc_us-gaap_InterestRateSwapMember_d603cec6-aa51-469c-aece-5860dac6cd0f" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_63fbf1b7-9556-40a7-b273-d2431bd664ea" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_6ce0a861-cd6a-4722-aec6-1c24b6b71475" xlink:to="loc_us-gaap_ForeignExchangeContractMember_63fbf1b7-9556-40a7-b273-d2431bd664ea" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmbeddedDerivativeFinancialInstrumentsMember_f7824a7e-878a-4413-86af-d6e9f4f79cd4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EmbeddedDerivativeFinancialInstrumentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_6ce0a861-cd6a-4722-aec6-1c24b6b71475" xlink:to="loc_us-gaap_EmbeddedDerivativeFinancialInstrumentsMember_f7824a7e-878a-4413-86af-d6e9f4f79cd4" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_TriggeringEventAxis_9c0fb56b-f638-4a61-8953-1eba2288373f" xlink:href="shc-20230331.xsd#shc_TriggeringEventAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_5c85202e-86e7-4704-b752-5017cd53b2b6" xlink:to="loc_shc_TriggeringEventAxis_9c0fb56b-f638-4a61-8953-1eba2288373f" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_TriggeringEventDomain_9c0fb56b-f638-4a61-8953-1eba2288373f_default" xlink:href="shc-20230331.xsd#shc_TriggeringEventDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_shc_TriggeringEventAxis_9c0fb56b-f638-4a61-8953-1eba2288373f" xlink:to="loc_shc_TriggeringEventDomain_9c0fb56b-f638-4a61-8953-1eba2288373f_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_TriggeringEventDomain_340840f9-af8e-4a55-89c2-6cb66d3343ad" xlink:href="shc-20230331.xsd#shc_TriggeringEventDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_shc_TriggeringEventAxis_9c0fb56b-f638-4a61-8953-1eba2288373f" xlink:to="loc_shc_TriggeringEventDomain_340840f9-af8e-4a55-89c2-6cb66d3343ad" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_ForwardStartDateBeginningOnJuly312023Member_ec4a8f05-e7da-46a9-8c89-14ec77c7035c" xlink:href="shc-20230331.xsd#shc_ForwardStartDateBeginningOnJuly312023Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_shc_TriggeringEventDomain_340840f9-af8e-4a55-89c2-6cb66d3343ad" xlink:to="loc_shc_ForwardStartDateBeginningOnJuly312023Member_ec4a8f05-e7da-46a9-8c89-14ec77c7035c" xlink:type="arc" order="0"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/FinancialInstrumentsandFinancialRiskScheduleofDerivativeInstrumentsGainLossDetails" xlink:type="simple" xlink:href="shc-20230331.xsd#FinancialInstrumentsandFinancialRiskScheduleofDerivativeInstrumentsGainLossDetails"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/FinancialInstrumentsandFinancialRiskScheduleofDerivativeInstrumentsGainLossDetails" xlink:type="extended" id="i441ef27dab9641d5a90d2cb060539191_FinancialInstrumentsandFinancialRiskScheduleofDerivativeInstrumentsGainLossDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_92896573-93a5-4ea3-8e7d-e795f8ab5e62" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeInstrumentsGainLossLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_UnrealizedGainLossOnDerivatives_3f225ef3-1c28-4bfa-b81b-1a9d00143828" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_UnrealizedGainLossOnDerivatives"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_92896573-93a5-4ea3-8e7d-e795f8ab5e62" xlink:to="loc_us-gaap_UnrealizedGainLossOnDerivatives_3f225ef3-1c28-4bfa-b81b-1a9d00143828" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeGainLossOnDerivativeNet_c15740ee-91ce-4d2e-95f0-f9e951b6be84" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeGainLossOnDerivativeNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_92896573-93a5-4ea3-8e7d-e795f8ab5e62" xlink:to="loc_us-gaap_DerivativeGainLossOnDerivativeNet_c15740ee-91ce-4d2e-95f0-f9e951b6be84" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_14accbd2-3811-4868-93db-7ff9d4995453" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossLineItems_92896573-93a5-4ea3-8e7d-e795f8ab5e62" xlink:to="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_14accbd2-3811-4868-93db-7ff9d4995453" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_e5bbb5e7-0775-48b4-b3aa-888345f97e9a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipByIncomeStatementLocationByDerivativeInstrumentRiskTable_14accbd2-3811-4868-93db-7ff9d4995453" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_e5bbb5e7-0775-48b4-b3aa-888345f97e9a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_e5bbb5e7-0775-48b4-b3aa-888345f97e9a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_e5bbb5e7-0775-48b4-b3aa-888345f97e9a" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_e5bbb5e7-0775-48b4-b3aa-888345f97e9a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_a2e6d4d8-1018-4feb-a05b-bb83c109b536" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_e5bbb5e7-0775-48b4-b3aa-888345f97e9a" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_a2e6d4d8-1018-4feb-a05b-bb83c109b536" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateCapMember_407c63bf-a916-4cd1-8be9-6474130b31b4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestRateCapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_a2e6d4d8-1018-4feb-a05b-bb83c109b536" xlink:to="loc_us-gaap_InterestRateCapMember_407c63bf-a916-4cd1-8be9-6474130b31b4" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmbeddedDerivativeFinancialInstrumentsMember_46aab5c4-36e6-4d7b-ab8c-76465a50e3fe" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EmbeddedDerivativeFinancialInstrumentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_a2e6d4d8-1018-4feb-a05b-bb83c109b536" xlink:to="loc_us-gaap_EmbeddedDerivativeFinancialInstrumentsMember_46aab5c4-36e6-4d7b-ab8c-76465a50e3fe" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_bf6c1380-e64a-45d4-ada1-12d243bd111e" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_a2e6d4d8-1018-4feb-a05b-bb83c109b536" xlink:to="loc_us-gaap_InterestRateSwapMember_bf6c1380-e64a-45d4-ada1-12d243bd111e" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeContractMember_e23d2a2f-44b8-4dbf-98e4-81d98a609bb7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ForeignExchangeContractMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_a2e6d4d8-1018-4feb-a05b-bb83c109b536" xlink:to="loc_us-gaap_ForeignExchangeContractMember_e23d2a2f-44b8-4dbf-98e4-81d98a609bb7" xlink:type="arc" order="3"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/FinancialInstrumentsandFinancialRiskScheduleofFairValueAssetsandLiabilitiesMeasuredonRecurringBasisDetails" xlink:type="simple" xlink:href="shc-20230331.xsd#FinancialInstrumentsandFinancialRiskScheduleofFairValueAssetsandLiabilitiesMeasuredonRecurringBasisDetails"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/FinancialInstrumentsandFinancialRiskScheduleofFairValueAssetsandLiabilitiesMeasuredonRecurringBasisDetails" xlink:type="extended" id="i2fb80cdbd09f4be3b48f9918d92ecce1_FinancialInstrumentsandFinancialRiskScheduleofFairValueAssetsandLiabilitiesMeasuredonRecurringBasisDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeLineItems_12b5a3fc-3673-45bd-a279-9cb384a98d3b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_f9c91f74-d6f7-4950-91c8-e8462c0bf5b8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeFairValueOfDerivativeAsset"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_12b5a3fc-3673-45bd-a279-9cb384a98d3b" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeAsset_f9c91f74-d6f7-4950-91c8-e8462c0bf5b8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_080ad388-fe17-426a-84fd-ba729444f473" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeFairValueOfDerivativeLiability"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_12b5a3fc-3673-45bd-a279-9cb384a98d3b" xlink:to="loc_us-gaap_DerivativeFairValueOfDerivativeLiability_080ad388-fe17-426a-84fd-ba729444f473" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_LongTermDebtCurrentMaturitiesFairValue_41399f03-3c13-44d2-b6ac-94edb02238c8" xlink:href="shc-20230331.xsd#shc_LongTermDebtCurrentMaturitiesFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_12b5a3fc-3673-45bd-a279-9cb384a98d3b" xlink:to="loc_shc_LongTermDebtCurrentMaturitiesFairValue_41399f03-3c13-44d2-b6ac-94edb02238c8" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LongTermDebtFairValue_8bae1c33-a870-470b-98ce-5848ce974e30" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LongTermDebtFairValue"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeLineItems_12b5a3fc-3673-45bd-a279-9cb384a98d3b" xlink:to="loc_us-gaap_LongTermDebtFairValue_8bae1c33-a870-470b-98ce-5848ce974e30" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeTable_bec8b4d5-2932-47ba-860e-352fc55a46d2" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_DerivativeLineItems_12b5a3fc-3673-45bd-a279-9cb384a98d3b" xlink:to="loc_us-gaap_DerivativeTable_bec8b4d5-2932-47ba-860e-352fc55a46d2" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationAxis_7ca2477c-23fe-42f2-9a9b-90e0dc496da5" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_HedgingDesignationAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_bec8b4d5-2932-47ba-860e-352fc55a46d2" xlink:to="loc_us-gaap_HedgingDesignationAxis_7ca2477c-23fe-42f2-9a9b-90e0dc496da5" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_7ca2477c-23fe-42f2-9a9b-90e0dc496da5_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_HedgingDesignationAxis_7ca2477c-23fe-42f2-9a9b-90e0dc496da5" xlink:to="loc_us-gaap_HedgingDesignationDomain_7ca2477c-23fe-42f2-9a9b-90e0dc496da5_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_HedgingDesignationDomain_b7dc5de4-828a-4165-a78a-d4710816f059" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_HedgingDesignationDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_HedgingDesignationAxis_7ca2477c-23fe-42f2-9a9b-90e0dc496da5" xlink:to="loc_us-gaap_HedgingDesignationDomain_b7dc5de4-828a-4165-a78a-d4710816f059" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DesignatedAsHedgingInstrumentMember_2df6ce99-3d80-47f4-9520-3f554b9d1a17" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DesignatedAsHedgingInstrumentMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_b7dc5de4-828a-4165-a78a-d4710816f059" xlink:to="loc_us-gaap_DesignatedAsHedgingInstrumentMember_2df6ce99-3d80-47f4-9520-3f554b9d1a17" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NondesignatedMember_e9782cf5-5eea-43cc-a4b0-c2bcf64da758" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NondesignatedMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_HedgingDesignationDomain_b7dc5de4-828a-4165-a78a-d4710816f059" xlink:to="loc_us-gaap_NondesignatedMember_e9782cf5-5eea-43cc-a4b0-c2bcf64da758" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByMeasurementBasisAxis_ffd4d67d-e980-42f6-9b5b-b85329982c3d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueByMeasurementBasisAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_bec8b4d5-2932-47ba-860e-352fc55a46d2" xlink:to="loc_us-gaap_FairValueByMeasurementBasisAxis_ffd4d67d-e980-42f6-9b5b-b85329982c3d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_ffd4d67d-e980-42f6-9b5b-b85329982c3d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_ffd4d67d-e980-42f6-9b5b-b85329982c3d" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_ffd4d67d-e980-42f6-9b5b-b85329982c3d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueDisclosureItemAmountsDomain_d0cdcdbb-42b9-45c0-b9fe-c34eb0928539" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueDisclosureItemAmountsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByMeasurementBasisAxis_ffd4d67d-e980-42f6-9b5b-b85329982c3d" xlink:to="loc_us-gaap_FairValueDisclosureItemAmountsDomain_d0cdcdbb-42b9-45c0-b9fe-c34eb0928539" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_a8d7e8fe-0ba8-4537-b507-a9f06f7c3808" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PortionAtFairValueFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueDisclosureItemAmountsDomain_d0cdcdbb-42b9-45c0-b9fe-c34eb0928539" xlink:to="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_a8d7e8fe-0ba8-4537-b507-a9f06f7c3808" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_6618595c-4933-4c56-bb89-7939d74b3b68" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CarryingReportedAmountFairValueDisclosureMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_PortionAtFairValueFairValueDisclosureMember_a8d7e8fe-0ba8-4537-b507-a9f06f7c3808" xlink:to="loc_us-gaap_CarryingReportedAmountFairValueDisclosureMember_6618595c-4933-4c56-bb89-7939d74b3b68" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeInstrumentRiskAxis_d22e73b9-339c-4466-8a01-4f776eca713a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeInstrumentRiskAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_bec8b4d5-2932-47ba-860e-352fc55a46d2" xlink:to="loc_us-gaap_DerivativeInstrumentRiskAxis_d22e73b9-339c-4466-8a01-4f776eca713a" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_d22e73b9-339c-4466-8a01-4f776eca713a_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_d22e73b9-339c-4466-8a01-4f776eca713a" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_d22e73b9-339c-4466-8a01-4f776eca713a_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DerivativeContractTypeDomain_28c099be-05ef-4f9d-b740-361b040c815a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DerivativeContractTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DerivativeInstrumentRiskAxis_d22e73b9-339c-4466-8a01-4f776eca713a" xlink:to="loc_us-gaap_DerivativeContractTypeDomain_28c099be-05ef-4f9d-b740-361b040c815a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateCapMember_96c35cfc-4e59-4631-84f4-ed746328528f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestRateCapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_28c099be-05ef-4f9d-b740-361b040c815a" xlink:to="loc_us-gaap_InterestRateCapMember_96c35cfc-4e59-4631-84f4-ed746328528f" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestRateSwapMember_b7e8cbf0-a21f-4d4a-b2d1-c7df7968c856" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestRateSwapMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_28c099be-05ef-4f9d-b740-361b040c815a" xlink:to="loc_us-gaap_InterestRateSwapMember_b7e8cbf0-a21f-4d4a-b2d1-c7df7968c856" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ForeignExchangeForwardMember_100bddaf-d143-4a3d-9a08-324807a99392" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ForeignExchangeForwardMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_28c099be-05ef-4f9d-b740-361b040c815a" xlink:to="loc_us-gaap_ForeignExchangeForwardMember_100bddaf-d143-4a3d-9a08-324807a99392" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_EmbeddedDerivativeFinancialInstrumentsMember_47ddfd6e-1bb5-4a06-bae1-3683655c22ee" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_EmbeddedDerivativeFinancialInstrumentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DerivativeContractTypeDomain_28c099be-05ef-4f9d-b740-361b040c815a" xlink:to="loc_us-gaap_EmbeddedDerivativeFinancialInstrumentsMember_47ddfd6e-1bb5-4a06-bae1-3683655c22ee" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_46b81f47-c190-4517-9f8b-faaabe32798b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_bec8b4d5-2932-47ba-860e-352fc55a46d2" xlink:to="loc_us-gaap_DebtInstrumentAxis_46b81f47-c190-4517-9f8b-faaabe32798b" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_46b81f47-c190-4517-9f8b-faaabe32798b_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_46b81f47-c190-4517-9f8b-faaabe32798b" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_46b81f47-c190-4517-9f8b-faaabe32798b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_7f6e3285-6191-4750-b5f6-1d71cb2a5095" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_46b81f47-c190-4517-9f8b-faaabe32798b" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_7f6e3285-6191-4750-b5f6-1d71cb2a5095" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_TermLoanBDue2026Member_05fcf3a3-2d0e-408f-a01e-2173d99cb807" xlink:href="shc-20230331.xsd#shc_TermLoanBDue2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7f6e3285-6191-4750-b5f6-1d71cb2a5095" xlink:to="loc_shc_TermLoanBDue2026Member_05fcf3a3-2d0e-408f-a01e-2173d99cb807" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_OtherLongTermDebtMember_4178c75b-a76c-4eda-b95f-cc5639f2edfd" xlink:href="shc-20230331.xsd#shc_OtherLongTermDebtMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7f6e3285-6191-4750-b5f6-1d71cb2a5095" xlink:to="loc_shc_OtherLongTermDebtMember_4178c75b-a76c-4eda-b95f-cc5639f2edfd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_TermLoanDue2026Member_f993e694-9d0f-4305-9f22-929ff42b6e86" xlink:href="shc-20230331.xsd#shc_TermLoanDue2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7f6e3285-6191-4750-b5f6-1d71cb2a5095" xlink:to="loc_shc_TermLoanDue2026Member_f993e694-9d0f-4305-9f22-929ff42b6e86" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevolvingCreditFacilityMember_a9e4cde4-4fdb-49a0-9b46-d7b3cc7a7fd3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevolvingCreditFacilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7f6e3285-6191-4750-b5f6-1d71cb2a5095" xlink:to="loc_us-gaap_RevolvingCreditFacilityMember_a9e4cde4-4fdb-49a0-9b46-d7b3cc7a7fd3" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_FinanceLeaseLiabilityMember_15504c7b-ca2c-4f69-8267-1c9d19b94751" xlink:href="shc-20230331.xsd#shc_FinanceLeaseLiabilityMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7f6e3285-6191-4750-b5f6-1d71cb2a5095" xlink:to="loc_shc_FinanceLeaseLiabilityMember_15504c7b-ca2c-4f69-8267-1c9d19b94751" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_e58d4136-8e7e-470b-b4e5-d1bc8db7f459" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_DerivativeTable_bec8b4d5-2932-47ba-860e-352fc55a46d2" xlink:to="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_e58d4136-8e7e-470b-b4e5-d1bc8db7f459" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_e58d4136-8e7e-470b-b4e5-d1bc8db7f459_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_e58d4136-8e7e-470b-b4e5-d1bc8db7f459" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_e58d4136-8e7e-470b-b4e5-d1bc8db7f459_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_c5af27b7-1528-41e8-b136-233d0f8d2afa" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueMeasurementsFairValueHierarchyDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_FairValueByFairValueHierarchyLevelAxis_e58d4136-8e7e-470b-b4e5-d1bc8db7f459" xlink:to="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_c5af27b7-1528-41e8-b136-233d0f8d2afa" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel1Member_1a9c22c6-4016-4364-8490-de4c6fc46133" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueInputsLevel1Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_c5af27b7-1528-41e8-b136-233d0f8d2afa" xlink:to="loc_us-gaap_FairValueInputsLevel1Member_1a9c22c6-4016-4364-8490-de4c6fc46133" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel2Member_a4c47a91-692a-4e55-8fa7-b3b3bb32d171" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueInputsLevel2Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_c5af27b7-1528-41e8-b136-233d0f8d2afa" xlink:to="loc_us-gaap_FairValueInputsLevel2Member_a4c47a91-692a-4e55-8fa7-b3b3bb32d171" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_FairValueInputsLevel3Member_29f05506-6908-4f6b-b740-8b2742ad1d7a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_FairValueInputsLevel3Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_FairValueMeasurementsFairValueHierarchyDomain_c5af27b7-1528-41e8-b136-233d0f8d2afa" xlink:to="loc_us-gaap_FairValueInputsLevel3Member_29f05506-6908-4f6b-b740-8b2742ad1d7a" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/SegmentInformationNarrativeDetails" xlink:type="simple" xlink:href="shc-20230331.xsd#SegmentInformationNarrativeDetails"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/SegmentInformationNarrativeDetails" xlink:type="extended" id="i27e69392a32048ee8baaf35844888863_SegmentInformationNarrativeDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_95c7de83-8008-43f0-bfab-555de60be076" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskPercentage1_14b079e3-b67b-4d91-b258-2f1f82853441" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskPercentage1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_95c7de83-8008-43f0-bfab-555de60be076" xlink:to="loc_us-gaap_ConcentrationRiskPercentage1_14b079e3-b67b-4d91-b258-2f1f82853441" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_f6e482c3-3a6c-4e18-825c-373249f04af7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_95c7de83-8008-43f0-bfab-555de60be076" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_f6e482c3-3a6c-4e18-825c-373249f04af7" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_a84dbb50-9788-47ae-8949-ab8a1b76195b" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_f6e482c3-3a6c-4e18-825c-373249f04af7" xlink:to="loc_srt_ConsolidationItemsAxis_a84dbb50-9788-47ae-8949-ab8a1b76195b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_a84dbb50-9788-47ae-8949-ab8a1b76195b_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_a84dbb50-9788-47ae-8949-ab8a1b76195b" xlink:to="loc_srt_ConsolidationItemsDomain_a84dbb50-9788-47ae-8949-ab8a1b76195b_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_5122376a-9a5f-4aa0-bba6-64fd10831553" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_a84dbb50-9788-47ae-8949-ab8a1b76195b" xlink:to="loc_srt_ConsolidationItemsDomain_5122376a-9a5f-4aa0-bba6-64fd10831553" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_35b7f42e-0df2-44dc-ba98-6491453dc7f6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_5122376a-9a5f-4aa0-bba6-64fd10831553" xlink:to="loc_us-gaap_OperatingSegmentsMember_35b7f42e-0df2-44dc-ba98-6491453dc7f6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_df2ab4a3-e85e-497d-9d76-e8617ea4d61d" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_f6e482c3-3a6c-4e18-825c-373249f04af7" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_df2ab4a3-e85e-497d-9d76-e8617ea4d61d" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_df2ab4a3-e85e-497d-9d76-e8617ea4d61d_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_df2ab4a3-e85e-497d-9d76-e8617ea4d61d" xlink:to="loc_us-gaap_SegmentDomain_df2ab4a3-e85e-497d-9d76-e8617ea4d61d_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_2f898975-5c49-4e6d-87c6-07c8d2fc80cd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_df2ab4a3-e85e-497d-9d76-e8617ea4d61d" xlink:to="loc_us-gaap_SegmentDomain_2f898975-5c49-4e6d-87c6-07c8d2fc80cd" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_NordionMember_b74682ce-15d2-4e0e-ba42-9bbae18a03c9" xlink:href="shc-20230331.xsd#shc_NordionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_2f898975-5c49-4e6d-87c6-07c8d2fc80cd" xlink:to="loc_shc_NordionMember_b74682ce-15d2-4e0e-ba42-9bbae18a03c9" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_e393c39a-e399-4d0e-89d8-6cecff5aae24" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_f6e482c3-3a6c-4e18-825c-373249f04af7" xlink:to="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_e393c39a-e399-4d0e-89d8-6cecff5aae24" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_e393c39a-e399-4d0e-89d8-6cecff5aae24_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_e393c39a-e399-4d0e-89d8-6cecff5aae24" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_e393c39a-e399-4d0e-89d8-6cecff5aae24_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskBenchmarkDomain_f09da991-201c-4cc6-a471-f3494f33d159" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskBenchmarkDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByBenchmarkAxis_e393c39a-e399-4d0e-89d8-6cecff5aae24" xlink:to="loc_us-gaap_ConcentrationRiskBenchmarkDomain_f09da991-201c-4cc6-a471-f3494f33d159" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerMember_c724e940-0f94-4e09-9975-aec1b23f8cce" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueFromContractWithCustomerMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskBenchmarkDomain_f09da991-201c-4cc6-a471-f3494f33d159" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerMember_c724e940-0f94-4e09-9975-aec1b23f8cce" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskByTypeAxis_44c9953a-3e47-4be4-b30d-9d13619dbbc4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskByTypeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_f6e482c3-3a6c-4e18-825c-373249f04af7" xlink:to="loc_us-gaap_ConcentrationRiskByTypeAxis_44c9953a-3e47-4be4-b30d-9d13619dbbc4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_44c9953a-3e47-4be4-b30d-9d13619dbbc4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_44c9953a-3e47-4be4-b30d-9d13619dbbc4" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_44c9953a-3e47-4be4-b30d-9d13619dbbc4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ConcentrationRiskTypeDomain_70984ca8-d66e-4e58-9918-2cc3b3ceeab8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ConcentrationRiskTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_ConcentrationRiskByTypeAxis_44c9953a-3e47-4be4-b30d-9d13619dbbc4" xlink:to="loc_us-gaap_ConcentrationRiskTypeDomain_70984ca8-d66e-4e58-9918-2cc3b3ceeab8" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_CustomerConcentrationRiskMember_76974e8e-b8d9-4486-b9ac-81435f6c1eb1" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_CustomerConcentrationRiskMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_ConcentrationRiskTypeDomain_70984ca8-d66e-4e58-9918-2cc3b3ceeab8" xlink:to="loc_us-gaap_CustomerConcentrationRiskMember_76974e8e-b8d9-4486-b9ac-81435f6c1eb1" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MajorCustomersAxis_6421d5c9-c145-4bc8-93c3-1295320bef92" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MajorCustomersAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_f6e482c3-3a6c-4e18-825c-373249f04af7" xlink:to="loc_srt_MajorCustomersAxis_6421d5c9-c145-4bc8-93c3-1295320bef92" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_6421d5c9-c145-4bc8-93c3-1295320bef92_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_MajorCustomersAxis_6421d5c9-c145-4bc8-93c3-1295320bef92" xlink:to="loc_srt_NameOfMajorCustomerDomain_6421d5c9-c145-4bc8-93c3-1295320bef92_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_NameOfMajorCustomerDomain_ab95dfb8-c681-4007-a4f9-21cf2a302de3" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_NameOfMajorCustomerDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_MajorCustomersAxis_6421d5c9-c145-4bc8-93c3-1295320bef92" xlink:to="loc_srt_NameOfMajorCustomerDomain_ab95dfb8-c681-4007-a4f9-21cf2a302de3" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_CustomerOneMember_56f57137-517c-4cbf-9bc3-21491255256e" xlink:href="shc-20230331.xsd#shc_CustomerOneMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_ab95dfb8-c681-4007-a4f9-21cf2a302de3" xlink:to="loc_shc_CustomerOneMember_56f57137-517c-4cbf-9bc3-21491255256e" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_CustomerTwoMember_30a41af1-b495-4198-9168-87dd1500f8d0" xlink:href="shc-20230331.xsd#shc_CustomerTwoMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_ab95dfb8-c681-4007-a4f9-21cf2a302de3" xlink:to="loc_shc_CustomerTwoMember_30a41af1-b495-4198-9168-87dd1500f8d0" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_CustomerThreeMember_bb4f63ff-7dbc-446f-9796-69960540d8d9" xlink:href="shc-20230331.xsd#shc_CustomerThreeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_ab95dfb8-c681-4007-a4f9-21cf2a302de3" xlink:to="loc_shc_CustomerThreeMember_bb4f63ff-7dbc-446f-9796-69960540d8d9" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_CustomerFourMember_db05aefb-77b3-49e5-b29c-4a221d0d67d2" xlink:href="shc-20230331.xsd#shc_CustomerFourMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_ab95dfb8-c681-4007-a4f9-21cf2a302de3" xlink:to="loc_shc_CustomerFourMember_db05aefb-77b3-49e5-b29c-4a221d0d67d2" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_CustomerFiveMember_88df76ab-7226-4274-a204-4f2f498ea5bb" xlink:href="shc-20230331.xsd#shc_CustomerFiveMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_NameOfMajorCustomerDomain_ab95dfb8-c681-4007-a4f9-21cf2a302de3" xlink:to="loc_shc_CustomerFiveMember_88df76ab-7226-4274-a204-4f2f498ea5bb" xlink:type="arc" order="4"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/SegmentInformationScheduleofSegmentReportingInformationbySegmentDetails" xlink:type="simple" xlink:href="shc-20230331.xsd#SegmentInformationScheduleofSegmentReportingInformationbySegmentDetails"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/SegmentInformationScheduleofSegmentReportingInformationbySegmentDetails" xlink:type="extended" id="i081c1fca7ee14dedab488f67bbf3ea28_SegmentInformationScheduleofSegmentReportingInformationbySegmentDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_40193039-63be-4141-a599-25b9971369ae" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_c992b97b-115a-47b6-9760-2d47f66af8dd" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_40193039-63be-4141-a599-25b9971369ae" xlink:to="loc_us-gaap_RevenueFromContractWithCustomerExcludingAssessedTax_c992b97b-115a-47b6-9760-2d47f66af8dd" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_SegmentIncomeLoss_9c78c807-a34c-4556-ba98-e2b4fe56ebbf" xlink:href="shc-20230331.xsd#shc_SegmentIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_40193039-63be-4141-a599-25b9971369ae" xlink:to="loc_shc_SegmentIncomeLoss_9c78c807-a34c-4556-ba98-e2b4fe56ebbf" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PaymentsToAcquireProductiveAssets_7136aeb7-c224-4435-82cd-48c20363eb47" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PaymentsToAcquireProductiveAssets"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_40193039-63be-4141-a599-25b9971369ae" xlink:to="loc_us-gaap_PaymentsToAcquireProductiveAssets_7136aeb7-c224-4435-82cd-48c20363eb47" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_c756a3ca-8155-4f35-8800-2e87d59a15d4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_40193039-63be-4141-a599-25b9971369ae" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_c756a3ca-8155-4f35-8800-2e87d59a15d4" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_c92aad8b-fec2-4311-8ea1-d0a9dc110c63" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_c756a3ca-8155-4f35-8800-2e87d59a15d4" xlink:to="loc_srt_ConsolidationItemsAxis_c92aad8b-fec2-4311-8ea1-d0a9dc110c63" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_c92aad8b-fec2-4311-8ea1-d0a9dc110c63_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_c92aad8b-fec2-4311-8ea1-d0a9dc110c63" xlink:to="loc_srt_ConsolidationItemsDomain_c92aad8b-fec2-4311-8ea1-d0a9dc110c63_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_8e65aef3-f0e9-437b-8fbf-cf7f2b636e7a" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_c92aad8b-fec2-4311-8ea1-d0a9dc110c63" xlink:to="loc_srt_ConsolidationItemsDomain_8e65aef3-f0e9-437b-8fbf-cf7f2b636e7a" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_f1b0a419-15f3-4372-98e4-0c6b10509594" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_8e65aef3-f0e9-437b-8fbf-cf7f2b636e7a" xlink:to="loc_us-gaap_OperatingSegmentsMember_f1b0a419-15f3-4372-98e4-0c6b10509594" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_IntersegmentEliminationMember_7ca82ceb-ec2e-472c-b36e-e5fbf91bfc54" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_IntersegmentEliminationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_8e65aef3-f0e9-437b-8fbf-cf7f2b636e7a" xlink:to="loc_us-gaap_IntersegmentEliminationMember_7ca82ceb-ec2e-472c-b36e-e5fbf91bfc54" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_StatementBusinessSegmentsAxis_72bd91af-9c85-45fe-8b44-6dec248d8f85" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_StatementBusinessSegmentsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_c756a3ca-8155-4f35-8800-2e87d59a15d4" xlink:to="loc_us-gaap_StatementBusinessSegmentsAxis_72bd91af-9c85-45fe-8b44-6dec248d8f85" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_72bd91af-9c85-45fe-8b44-6dec248d8f85_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_72bd91af-9c85-45fe-8b44-6dec248d8f85" xlink:to="loc_us-gaap_SegmentDomain_72bd91af-9c85-45fe-8b44-6dec248d8f85_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentDomain_c3b82195-3a42-4869-bdb3-dbcc5128aeb7" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_StatementBusinessSegmentsAxis_72bd91af-9c85-45fe-8b44-6dec248d8f85" xlink:to="loc_us-gaap_SegmentDomain_c3b82195-3a42-4869-bdb3-dbcc5128aeb7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_SterigenicsMember_49081305-f2be-49bc-a616-36ffecd8c32b" xlink:href="shc-20230331.xsd#shc_SterigenicsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_c3b82195-3a42-4869-bdb3-dbcc5128aeb7" xlink:to="loc_shc_SterigenicsMember_49081305-f2be-49bc-a616-36ffecd8c32b" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_NordionMember_084360cc-24d5-4c1f-a4ad-f840ecce9fcc" xlink:href="shc-20230331.xsd#shc_NordionMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_c3b82195-3a42-4869-bdb3-dbcc5128aeb7" xlink:to="loc_shc_NordionMember_084360cc-24d5-4c1f-a4ad-f840ecce9fcc" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_NelsonLabsMember_5180008a-f89d-48e4-b0a1-0d2686ac0566" xlink:href="shc-20230331.xsd#shc_NelsonLabsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentDomain_c3b82195-3a42-4869-bdb3-dbcc5128aeb7" xlink:to="loc_shc_NelsonLabsMember_5180008a-f89d-48e4-b0a1-0d2686ac0566" xlink:type="arc" order="2"/>
  </link:definitionLink>
  <link:roleRef roleURI="http://soterahealth.com/role/SegmentInformationScheduleofReconciliationofOperatingProfitLossfromSegmentstoConsolidatedDetails" xlink:type="simple" xlink:href="shc-20230331.xsd#SegmentInformationScheduleofReconciliationofOperatingProfitLossfromSegmentstoConsolidatedDetails"/>
  <link:definitionLink xlink:role="http://soterahealth.com/role/SegmentInformationScheduleofReconciliationofOperatingProfitLossfromSegmentstoConsolidatedDetails" xlink:type="extended" id="iec09b3f5f23c4678910e642683059166_SegmentInformationScheduleofReconciliationofOperatingProfitLossfromSegmentstoConsolidatedDetails">
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_SegmentReportingInformationLineItems_a7ce2eff-349a-4406-8b0a-e2c296b3ae21" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_SegmentReportingInformationLineItems"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_SegmentIncomeLoss_3c754acb-3167-442b-b314-eceb030de61d" xlink:href="shc-20230331.xsd#shc_SegmentIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_a7ce2eff-349a-4406-8b0a-e2c296b3ae21" xlink:to="loc_shc_SegmentIncomeLoss_3c754acb-3167-442b-b314-eceb030de61d" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_InterestExpense_f8f60538-e317-4e3a-95eb-560dd4b6a53b" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_InterestExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_a7ce2eff-349a-4406-8b0a-e2c296b3ae21" xlink:to="loc_us-gaap_InterestExpense_f8f60538-e317-4e3a-95eb-560dd4b6a53b" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DepreciationDepletionAndAmortization_a7741f9c-8969-467d-988c-5da0d54857c3" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DepreciationDepletionAndAmortization"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_a7ce2eff-349a-4406-8b0a-e2c296b3ae21" xlink:to="loc_us-gaap_DepreciationDepletionAndAmortization_a7741f9c-8969-467d-988c-5da0d54857c3" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ShareBasedCompensation_a8e45a29-52f0-478a-853d-188a259c7cc0" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ShareBasedCompensation"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_a7ce2eff-349a-4406-8b0a-e2c296b3ae21" xlink:to="loc_us-gaap_ShareBasedCompensation_a8e45a29-52f0-478a-853d-188a259c7cc0" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_ForeignCurrencyGainLossAndGainLossOnEmbeddedDerivative_60fcc132-bc72-4e73-8eff-b876be6a7523" xlink:href="shc-20230331.xsd#shc_ForeignCurrencyGainLossAndGainLossOnEmbeddedDerivative"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_a7ce2eff-349a-4406-8b0a-e2c296b3ae21" xlink:to="loc_shc_ForeignCurrencyGainLossAndGainLossOnEmbeddedDerivative_60fcc132-bc72-4e73-8eff-b876be6a7523" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_AcquisitionAndDivestitureRelatedChargesNet_4c62c22e-90bf-4965-8e66-51adb440d527" xlink:href="shc-20230331.xsd#shc_AcquisitionAndDivestitureRelatedChargesNet"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_a7ce2eff-349a-4406-8b0a-e2c296b3ae21" xlink:to="loc_shc_AcquisitionAndDivestitureRelatedChargesNet_4c62c22e-90bf-4965-8e66-51adb440d527" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OtherRestructuringCosts_86f1677a-e32f-485c-95ea-8892eb8869af" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OtherRestructuringCosts"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_a7ce2eff-349a-4406-8b0a-e2c296b3ae21" xlink:to="loc_us-gaap_OtherRestructuringCosts_86f1677a-e32f-485c-95ea-8892eb8869af" xlink:type="arc" order="6"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_BusinessExitCosts1_816978d9-f9b3-49a0-88ec-8a4cdeb032b9" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_BusinessExitCosts1"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_a7ce2eff-349a-4406-8b0a-e2c296b3ae21" xlink:to="loc_us-gaap_BusinessExitCosts1_816978d9-f9b3-49a0-88ec-8a4cdeb032b9" xlink:type="arc" order="7"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationSettlementExpense_20d9c333-8280-42d6-a242-8887f90b779f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LitigationSettlementExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_a7ce2eff-349a-4406-8b0a-e2c296b3ae21" xlink:to="loc_us-gaap_LitigationSettlementExpense_20d9c333-8280-42d6-a242-8887f90b779f" xlink:type="arc" order="8"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_AssetRetirementObligationAccretionExpense_d07031d9-0ab0-4a8c-a0f7-576efc4543ee" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_AssetRetirementObligationAccretionExpense"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_a7ce2eff-349a-4406-8b0a-e2c296b3ae21" xlink:to="loc_us-gaap_AssetRetirementObligationAccretionExpense_d07031d9-0ab0-4a8c-a0f7-576efc4543ee" xlink:type="arc" order="9"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_CostAndExpensesCOVID19_010aead3-c231-467c-9d27-572ce872370a" xlink:href="shc-20230331.xsd#shc_CostAndExpensesCOVID19"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_a7ce2eff-349a-4406-8b0a-e2c296b3ae21" xlink:to="loc_shc_CostAndExpensesCOVID19_010aead3-c231-467c-9d27-572ce872370a" xlink:type="arc" order="10"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_NetIncomeLoss_db140810-a213-430e-ae6c-4875d567c77a" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_NetIncomeLoss"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_a7ce2eff-349a-4406-8b0a-e2c296b3ae21" xlink:to="loc_us-gaap_NetIncomeLoss_db140810-a213-430e-ae6c-4875d567c77a" xlink:type="arc" order="11"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationSettlementAmountAwardedToOtherParty_3d2e63e1-c62b-468c-94b5-64589c162681" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LitigationSettlementAmountAwardedToOtherParty"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_a7ce2eff-349a-4406-8b0a-e2c296b3ae21" xlink:to="loc_us-gaap_LitigationSettlementAmountAwardedToOtherParty_3d2e63e1-c62b-468c-94b5-64589c162681" xlink:type="arc" order="12"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_GainLossOnInterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstruments_67d8fbfc-15fc-4db2-b9a7-993711a53d1c" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_GainLossOnInterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstruments"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_a7ce2eff-349a-4406-8b0a-e2c296b3ae21" xlink:to="loc_us-gaap_GainLossOnInterestRateDerivativeInstrumentsNotDesignatedAsHedgingInstruments_67d8fbfc-15fc-4db2-b9a7-993711a53d1c" xlink:type="arc" order="13"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_CancellationFeeReceivedForLeaseTermination_b1c30384-0d37-4efd-94e7-90e831edbe2a" xlink:href="shc-20230331.xsd#shc_CancellationFeeReceivedForLeaseTermination"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_a7ce2eff-349a-4406-8b0a-e2c296b3ae21" xlink:to="loc_shc_CancellationFeeReceivedForLeaseTermination_b1c30384-0d37-4efd-94e7-90e831edbe2a" xlink:type="arc" order="14"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LossContingencyPendingClaimsNumber_d2ac4271-b89b-46e2-ab16-5d55e75ff1ea" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LossContingencyPendingClaimsNumber"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_a7ce2eff-349a-4406-8b0a-e2c296b3ae21" xlink:to="loc_us-gaap_LossContingencyPendingClaimsNumber_d2ac4271-b89b-46e2-ab16-5d55e75ff1ea" xlink:type="arc" order="15"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_fabb8e0b-5512-4811-9145-8d09d5bdec4f" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/all" xlink:from="loc_us-gaap_SegmentReportingInformationLineItems_a7ce2eff-349a-4406-8b0a-e2c296b3ae21" xlink:to="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_fabb8e0b-5512-4811-9145-8d09d5bdec4f" xlink:type="arc" order="1" xbrldt:closed="true" xbrldt:contextElement="segment"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsAxis_09ddbd78-1282-4a97-bc4a-2d8100a733a7" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_fabb8e0b-5512-4811-9145-8d09d5bdec4f" xlink:to="loc_srt_ConsolidationItemsAxis_09ddbd78-1282-4a97-bc4a-2d8100a733a7" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_09ddbd78-1282-4a97-bc4a-2d8100a733a7_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_ConsolidationItemsAxis_09ddbd78-1282-4a97-bc4a-2d8100a733a7" xlink:to="loc_srt_ConsolidationItemsDomain_09ddbd78-1282-4a97-bc4a-2d8100a733a7_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_ConsolidationItemsDomain_5bbe8428-fb37-4aa4-8f77-56e0ac849be1" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_ConsolidationItemsDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_ConsolidationItemsAxis_09ddbd78-1282-4a97-bc4a-2d8100a733a7" xlink:to="loc_srt_ConsolidationItemsDomain_5bbe8428-fb37-4aa4-8f77-56e0ac849be1" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_OperatingSegmentsMember_406ddf16-1b35-4fd5-92b5-68dbbafc08e6" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_OperatingSegmentsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_5bbe8428-fb37-4aa4-8f77-56e0ac849be1" xlink:to="loc_us-gaap_OperatingSegmentsMember_406ddf16-1b35-4fd5-92b5-68dbbafc08e6" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_MaterialReconcilingItemsMember_2ff67b91-56d5-4fef-ab32-b7aac022a1d4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_MaterialReconcilingItemsMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_ConsolidationItemsDomain_5bbe8428-fb37-4aa4-8f77-56e0ac849be1" xlink:to="loc_us-gaap_MaterialReconcilingItemsMember_2ff67b91-56d5-4fef-ab32-b7aac022a1d4" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentAxis_6cb75c33-c6b8-44d7-bbae-130d5d5dc686" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_fabb8e0b-5512-4811-9145-8d09d5bdec4f" xlink:to="loc_us-gaap_DebtInstrumentAxis_6cb75c33-c6b8-44d7-bbae-130d5d5dc686" xlink:type="arc" order="2"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_6cb75c33-c6b8-44d7-bbae-130d5d5dc686_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_DebtInstrumentAxis_6cb75c33-c6b8-44d7-bbae-130d5d5dc686" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_6cb75c33-c6b8-44d7-bbae-130d5d5dc686_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_DebtInstrumentNameDomain_7398a206-bd0b-4525-83fe-50259c311afb" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_DebtInstrumentNameDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_DebtInstrumentAxis_6cb75c33-c6b8-44d7-bbae-130d5d5dc686" xlink:to="loc_us-gaap_DebtInstrumentNameDomain_7398a206-bd0b-4525-83fe-50259c311afb" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_TermLoanBDue2026Member_e7919c6c-ebd3-460b-b5d6-e57bf779d163" xlink:href="shc-20230331.xsd#shc_TermLoanBDue2026Member"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_DebtInstrumentNameDomain_7398a206-bd0b-4525-83fe-50259c311afb" xlink:to="loc_shc_TermLoanBDue2026Member_e7919c6c-ebd3-460b-b5d6-e57bf779d163" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseAxis_9141adba-c426-4aff-b6b8-b9c2b184c3dd" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_LitigationCaseAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_fabb8e0b-5512-4811-9145-8d09d5bdec4f" xlink:to="loc_srt_LitigationCaseAxis_9141adba-c426-4aff-b6b8-b9c2b184c3dd" xlink:type="arc" order="3"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseTypeDomain_9141adba-c426-4aff-b6b8-b9c2b184c3dd_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_LitigationCaseTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_LitigationCaseAxis_9141adba-c426-4aff-b6b8-b9c2b184c3dd" xlink:to="loc_srt_LitigationCaseTypeDomain_9141adba-c426-4aff-b6b8-b9c2b184c3dd_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_LitigationCaseTypeDomain_32e8737e-f3b6-48b3-9110-a947fe4a4634" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_LitigationCaseTypeDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_LitigationCaseAxis_9141adba-c426-4aff-b6b8-b9c2b184c3dd" xlink:to="loc_srt_LitigationCaseTypeDomain_32e8737e-f3b6-48b3-9110-a947fe4a4634" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_shc_EthyleneOxideTortLitigationIllinoisMember_700d79fd-3d28-4560-bf97-80e255b9a266" xlink:href="shc-20230331.xsd#shc_EthyleneOxideTortLitigationIllinoisMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_LitigationCaseTypeDomain_32e8737e-f3b6-48b3-9110-a947fe4a4634" xlink:to="loc_shc_EthyleneOxideTortLitigationIllinoisMember_700d79fd-3d28-4560-bf97-80e255b9a266" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusAxis_71ab511e-8227-417d-b425-902742469bc4" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LitigationStatusAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_fabb8e0b-5512-4811-9145-8d09d5bdec4f" xlink:to="loc_us-gaap_LitigationStatusAxis_71ab511e-8227-417d-b425-902742469bc4" xlink:type="arc" order="4"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusDomain_71ab511e-8227-417d-b425-902742469bc4_default" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LitigationStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_us-gaap_LitigationStatusAxis_71ab511e-8227-417d-b425-902742469bc4" xlink:to="loc_us-gaap_LitigationStatusDomain_71ab511e-8227-417d-b425-902742469bc4_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_LitigationStatusDomain_c6aeb917-6ba9-47bc-8912-faaf7c7ff308" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_LitigationStatusDomain"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_us-gaap_LitigationStatusAxis_71ab511e-8227-417d-b425-902742469bc4" xlink:to="loc_us-gaap_LitigationStatusDomain_c6aeb917-6ba9-47bc-8912-faaf7c7ff308" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_us-gaap_PendingLitigationMember_8c4f7698-5a1e-4650-8470-61bf953892f8" xlink:href="https://xbrl.fasb.org/us-gaap/2022/elts/us-gaap-2022.xsd#us-gaap_PendingLitigationMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_us-gaap_LitigationStatusDomain_c6aeb917-6ba9-47bc-8912-faaf7c7ff308" xlink:to="loc_us-gaap_PendingLitigationMember_8c4f7698-5a1e-4650-8470-61bf953892f8" xlink:type="arc" order="0"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeAxis_05130847-37ae-46b6-b43d-5403c8e45c3e" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeAxis"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/hypercube-dimension" xlink:from="loc_us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_fabb8e0b-5512-4811-9145-8d09d5bdec4f" xlink:to="loc_srt_RangeAxis_05130847-37ae-46b6-b43d-5403c8e45c3e" xlink:type="arc" order="5"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_05130847-37ae-46b6-b43d-5403c8e45c3e_default" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-default" xlink:from="loc_srt_RangeAxis_05130847-37ae-46b6-b43d-5403c8e45c3e" xlink:to="loc_srt_RangeMember_05130847-37ae-46b6-b43d-5403c8e45c3e_default" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_RangeMember_e9de40e0-2440-4336-a6f1-8c3101e02295" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_RangeMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/dimension-domain" xlink:from="loc_srt_RangeAxis_05130847-37ae-46b6-b43d-5403c8e45c3e" xlink:to="loc_srt_RangeMember_e9de40e0-2440-4336-a6f1-8c3101e02295" xlink:type="arc" order="1"/>
    <link:loc xlink:type="locator" xlink:label="loc_srt_MinimumMember_7028fd84-46ec-4282-81f8-db8179eb281c" xlink:href="https://xbrl.fasb.org/srt/2022/elts/srt-2022.xsd#srt_MinimumMember"/>
    <link:definitionArc xlink:arcrole="http://xbrl.org/int/dim/arcrole/domain-member" xlink:from="loc_srt_RangeMember_e9de40e0-2440-4336-a6f1-8c3101e02295" xlink:to="loc_srt_MinimumMember_7028fd84-46ec-4282-81f8-db8179eb281c" xlink:type="arc" order="0"/>
  </link:definitionLink>
</link:linkbase>
