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        <link:definition>9952165 - Disclosure - GOODWILL AND INTANGIBLE ASSETS</link:definition>
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        <link:definition>9955512 - Disclosure - EARNINGS PER SHARE (Tables)</link:definition>
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        <link:definition>9955522 - Disclosure - SHAREHOLDERS' EQUITY (Tables)</link:definition>
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        <link:definition>9955524 - Disclosure - DERIVATIVE FINANCIAL INSTRUMENTS (Tables)</link:definition>
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        <link:definition>9955525 - Disclosure - RECENT ACCOUNTING PRONOUNCEMENTS (Details)</link:definition>
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        <link:definition>9955527 - Disclosure - RESTRUCTURING CHARGES (Details 1)</link:definition>
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        <link:definition>9955528 - Disclosure - RESTRUCTURING CHARGES (Details 2)</link:definition>
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        <link:definition>9955530 - Disclosure - EARNINGS PER SHARE (Details)</link:definition>
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        <link:definition>9955531 - Disclosure - ACCOUNTS RECEIVABLES (Details)</link:definition>
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  <xs:element id="oln_PerformanceShareAwardWeightedAverageFVPerShare" abstract="false" name="PerformanceShareAwardWeightedAverageFVPerShare" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:perShareItemType"/>
  <xs:element id="oln_PerformanceShareAwardPayoutRangeLow" abstract="false" name="PerformanceShareAwardPayoutRangeLow" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="oln_PerformanceShareAwardNetIncomePercent" abstract="false" name="PerformanceShareAwardNetIncomePercent" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:percentItemType"/>
  <xs:element id="oln_PerformanceShareAwardsSharesGranted" abstract="false" name="PerformanceShareAwardsSharesGranted" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="oln_A2022ShareRepurchaseProgramMember" abstract="true" name="A2022ShareRepurchaseProgramMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oln_A2024ShareRepurchaseProgramMember" abstract="true" name="A2024ShareRepurchaseProgramMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="oln_ForeignCurrencyTranslationAdjustmentRollForward" abstract="true" name="ForeignCurrencyTranslationAdjustmentRollForward" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="oln_UnrealizedGainsLossesOnDerivativeContractsSummaryRollForward" abstract="true" name="UnrealizedGainsLossesOnDerivativeContractsSummaryRollForward" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="oln_PensionAndPostretirementBenefitsSummaryRollForward" abstract="true" name="PensionAndPostretirementBenefitsSummaryRollForward" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="oln_AccumulatedOtherComprehensiveLossRollForward" abstract="true" name="AccumulatedOtherComprehensiveLossRollForward" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="oln_OtherComprehensiveIncomeLossNetGainLossRecognizedBeforeTax" abstract="false" name="OtherComprehensiveIncomeLossNetGainLossRecognizedBeforeTax" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="oln_OtherComprehensiveIncomeLossReclassificationAdjustmentBeforeTax" abstract="false" name="OtherComprehensiveIncomeLossReclassificationAdjustmentBeforeTax" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="oln_CorporateOtherMember" abstract="true" name="CorporateOtherMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="oln_OtherforeignMember" abstract="true" name="OtherforeignMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oln_NonOperatingPensionIncome" abstract="false" name="NonOperatingPensionIncome" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="oln_CausticsodaMember" abstract="true" name="CausticsodaMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oln_ChlorinechlorinederivativesandothercoproductsMember" abstract="true" name="ChlorinechlorinederivativesandothercoproductsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oln_AromaticsandallylicsMember" abstract="true" name="AromaticsandallylicsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oln_EpoxyresinsMember" abstract="true" name="EpoxyresinsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oln_CommercialMember" abstract="true" name="CommercialMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oln_MilitaryandlawenforcementMember" abstract="true" name="MilitaryandlawenforcementMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oln_AdditionalAccruedLitigationContingency" abstract="false" name="AdditionalAccruedLitigationContingency" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="oln_AccruedLitigationContingency" abstract="false" name="AccruedLitigationContingency" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="oln_LitigationTable" abstract="true" name="LitigationTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="oln_ShintechMember" abstract="true" name="ShintechMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="oln_ForwardContractsSellMember" abstract="true" name="ForwardContractsSellMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oln_NaturalGasCommodityForwardContractsMember" abstract="true" name="NaturalGasCommodityForwardContractsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oln_MetalsCommodityForwardContractsMember" abstract="true" name="MetalsCommodityForwardContractsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oln_CommodityContractsGainsMember" abstract="true" name="CommodityContractsGainsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oln_ForeignExchangeContractGainMember" abstract="true" name="ForeignExchangeContractGainMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oln_CommodityContractsLossesMember" abstract="true" name="CommodityContractsLossesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oln_ForeignExchangeContractLossMember" abstract="true" name="ForeignExchangeContractLossMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
  <xs:element id="oln_IncomeStatementLocationDerivativesAxis" abstract="true" name="IncomeStatementLocationDerivativesAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="oln_IncomeStatementLocationDerivativesDomain" abstract="true" name="IncomeStatementLocationDerivativesDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types1:domainItemType"/>
</xs:schema>
