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

<!--XBRL Document Created with the Workiva Platform-->
<!--Copyright 2026 Workiva-->
<!--r:019b230c-2918-7516-91bb-d493fb8b26ca,g:a8c0d1c2-7417-4fb5-8f09-5f95eaa01619-->
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:frme="http://www.firstmerchants.com/20260611" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:dtr-types="http://www.xbrl.org/dtr/type/2024-01-31" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" attributeFormDefault="unqualified" elementFormDefault="qualified" targetNamespace="http://www.firstmerchants.com/20260611">
  <xs:import namespace="http://fasb.org/srt/2025" schemaLocation="https://xbrl.fasb.org/srt/2025/elts/srt-2025.xsd"/>
  <xs:import namespace="http://fasb.org/us-gaap-ebp/2025" schemaLocation="https://xbrl.fasb.org/us-gaap/2025/ebp/elts/us-gaap-ebp-2025.xsd"/>
  <xs:import namespace="http://fasb.org/us-gaap/2025" schemaLocation="https://xbrl.fasb.org/us-gaap/2025/elts/us-gaap-2025.xsd"/>
  <xs:import namespace="http://www.xbrl.org/2003/instance" schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd"/>
  <xs:import namespace="http://www.xbrl.org/2003/linkbase" schemaLocation="http://www.xbrl.org/2003/xbrl-linkbase-2003-12-31.xsd"/>
  <xs:import namespace="http://www.xbrl.org/dtr/type/2024-01-31" schemaLocation="https://www.xbrl.org/dtr/type/2024-01-31/types.xsd"/>
  <xs:import namespace="http://xbrl.org/2005/xbrldt" schemaLocation="http://www.xbrl.org/2005/xbrldt-2005.xsd"/>
  <xs:import namespace="http://xbrl.sec.gov/dei/2025" schemaLocation="https://xbrl.sec.gov/dei/2025/dei-2025.xsd"/>
  <xs:annotation>
    <xs:appinfo>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="frme-20260611_pre.xml" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="frme-20260611_def.xml" xlink:role="http://www.xbrl.org/2003/role/definitionLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="frme-20260611_lab.xml" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:type="simple"/>
      <link:linkbaseRef xmlns:xlink="http://www.w3.org/1999/xlink" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" xlink:href="frme-20260611_cal.xml" xlink:role="http://www.xbrl.org/2003/role/calculationLinkbaseRef" xlink:type="simple"/>
      <link:roleType id="Cover" roleURI="http://www.firstmerchants.com/role/Cover">
        <link:definition>0000001 - Document - Cover</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="StatementsofNetAssetsAvailableforBenefits" roleURI="http://www.firstmerchants.com/role/StatementsofNetAssetsAvailableforBenefits">
        <link:definition>0000002 - Statement - Statements of Net Assets Available for Benefits</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="StatementsofChangesinNetAssetsAvailableforBenefits" roleURI="http://www.firstmerchants.com/role/StatementsofChangesinNetAssetsAvailableforBenefits">
        <link:definition>0000003 - Statement - Statements of Changes in Net Assets Available for Benefits</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DESCRIPTIONOFPLAN" roleURI="http://www.firstmerchants.com/role/DESCRIPTIONOFPLAN">
        <link:definition>0000004 - Disclosure - DESCRIPTION OF PLAN</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIES" roleURI="http://www.firstmerchants.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIES">
        <link:definition>0000005 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DISCLOSURESABOUTFAIRVALUEOFASSETSANDLIABILITIES" roleURI="http://www.firstmerchants.com/role/DISCLOSURESABOUTFAIRVALUEOFASSETSANDLIABILITIES">
        <link:definition>0000006 - Disclosure - DISCLOSURES ABOUT FAIR VALUE OF ASSETS AND LIABILITIES</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="INVESTMENTCONTRACTWITHINSURANCECOMPANY" roleURI="http://www.firstmerchants.com/role/INVESTMENTCONTRACTWITHINSURANCECOMPANY">
        <link:definition>0000007 - Disclosure - INVESTMENT CONTRACT WITH INSURANCE COMPANY</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PARTYININTERESTTRANSACTIONS" roleURI="http://www.firstmerchants.com/role/PARTYININTERESTTRANSACTIONS">
        <link:definition>0000008 - Disclosure - PARTY-IN-INTEREST TRANSACTIONS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="RISKSANDUNCERTAINTIES" roleURI="http://www.firstmerchants.com/role/RISKSANDUNCERTAINTIES">
        <link:definition>0000009 - Disclosure - RISKS AND UNCERTAINTIES</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="NONEXEMPTTRANSACTIONS" roleURI="http://www.firstmerchants.com/role/NONEXEMPTTRANSACTIONS">
        <link:definition>0000010 - Disclosure - NONEXEMPT TRANSACTIONS</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SUBSEQUENTEVENT" roleURI="http://www.firstmerchants.com/role/SUBSEQUENTEVENT">
        <link:definition>0000011 - Disclosure - SUBSEQUENT EVENT</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ScheduleHLine4iScheduleofAssetsHeldAtEndofYear" roleURI="http://www.firstmerchants.com/role/ScheduleHLine4iScheduleofAssetsHeldAtEndofYear">
        <link:definition>0000012 - Disclosure - Schedule H, Line 4i &#8211; Schedule of Assets (Held At End of Year)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPolicies" roleURI="http://www.firstmerchants.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESPolicies">
        <link:definition>0000013 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Policies)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTables" roleURI="http://www.firstmerchants.com/role/SUMMARYOFSIGNIFICANTACCOUNTINGPOLICIESTables">
        <link:definition>0000014 - Disclosure - SUMMARY OF SIGNIFICANT ACCOUNTING POLICIES (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DISCLOSURESABOUTFAIRVALUEOFASSETSANDLIABILITIESTables" roleURI="http://www.firstmerchants.com/role/DISCLOSURESABOUTFAIRVALUEOFASSETSANDLIABILITIESTables">
        <link:definition>0000015 - Disclosure - DISCLOSURES ABOUT FAIR VALUE OF ASSETS AND LIABILITIES (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PARTYININTERESTTRANSACTIONSTables" roleURI="http://www.firstmerchants.com/role/PARTYININTERESTTRANSACTIONSTables">
        <link:definition>0000016 - Disclosure - PARTY-IN-INTEREST TRANSACTIONS (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DESCRIPTIONOFPLANDetails" roleURI="http://www.firstmerchants.com/role/DESCRIPTIONOFPLANDetails">
        <link:definition>0000017 - Disclosure - DESCRIPTION OF PLAN (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="DISCLOSURESABOUTFAIRVALUEOFASSETSANDLIABILITIESDetails" roleURI="http://www.firstmerchants.com/role/DISCLOSURESABOUTFAIRVALUEOFASSETSANDLIABILITIESDetails">
        <link:definition>0000018 - Disclosure - DISCLOSURES ABOUT FAIR VALUE OF ASSETS AND LIABILITIES (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="INVESTMENTCONTRACTWITHINSURANCECOMPANYDetails" roleURI="http://www.firstmerchants.com/role/INVESTMENTCONTRACTWITHINSURANCECOMPANYDetails">
        <link:definition>0000019 - Disclosure - INVESTMENT CONTRACT WITH INSURANCE COMPANY (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PARTYININTERESTTRANSACTIONSNarrativeDetails" roleURI="http://www.firstmerchants.com/role/PARTYININTERESTTRANSACTIONSNarrativeDetails">
        <link:definition>0000020 - Disclosure - PARTY-IN-INTEREST TRANSACTIONS - Narrative (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="PARTYININTERESTTRANSACTIONSScheduleofRelatedPartyTransactionsDetails" roleURI="http://www.firstmerchants.com/role/PARTYININTERESTTRANSACTIONSScheduleofRelatedPartyTransactionsDetails">
        <link:definition>0000021 - Disclosure - PARTY-IN-INTEREST TRANSACTIONS - Schedule of Related Party Transactions (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="NONEXEMPTTRANSACTIONDetails" roleURI="http://www.firstmerchants.com/role/NONEXEMPTTRANSACTIONDetails">
        <link:definition>0000022 - Disclosure - NONEXEMPT TRANSACTION (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ScheduleHLine4iScheduleofAssetsHeldAtEndofYearDetails" roleURI="http://www.firstmerchants.com/role/ScheduleHLine4iScheduleofAssetsHeldAtEndofYearDetails">
        <link:definition>0000023 - Disclosure - Schedule H, Line 4i &#8211; Schedule of Assets (Held At End of Year) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType id="ScheduleHLine4iScheduleofAssetsHeldAtEndofYearDetails_1" roleURI="http://www.firstmerchants.com/role/ScheduleHLine4iScheduleofAssetsHeldAtEndofYearDetails_1">
        <link:definition>0000023 - Disclosure - Schedule H, Line 4i &#8211; Schedule of Assets (Held At End of Year) (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
    </xs:appinfo>
  </xs:annotation>
  <xs:element id="frme_EBP002Member" abstract="true" name="EBP002Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="frme_EBPEmployerContributionTypeAxis" abstract="true" name="EBPEmployerContributionTypeAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="frme_EBPEmployerContributionTypeDomain" abstract="true" name="EBPEmployerContributionTypeDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="frme_EBPRetirementSecurityContributionRSCMember" abstract="true" name="EBPRetirementSecurityContributionRSCMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="frme_EBPEmployerMatchingContributionsMember" abstract="true" name="EBPEmployerMatchingContributionsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="frme_EBPEmployerMatchingContributionsTrancheOneMember" abstract="true" name="EBPEmployerMatchingContributionsTrancheOneMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="frme_EBPEmployerMatchingContributionsTrancheTwoMember" abstract="true" name="EBPEmployerMatchingContributionsTrancheTwoMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="frme_EBPRequisiteParticipantAge" abstract="false" name="EBPRequisiteParticipantAge" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="frme_EBPEmployerContributionAnnualFixedRateContributionPercentage" abstract="false" name="EBPEmployerContributionAnnualFixedRateContributionPercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="frme_EBPRequisiteServiceHours" abstract="false" name="EBPRequisiteServiceHours" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="frme_EBPRetirementAge" abstract="false" name="EBPRetirementAge" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="frme_EBPRetirementServicePeriod" abstract="false" name="EBPRetirementServicePeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="frme_EBPParticipantContributionAutomaticDeferralDeclinePeriod" abstract="false" name="EBPParticipantContributionAutomaticDeferralDeclinePeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="frme_EBPParticipantAccountMaximumPlanInvestmentBalancePercent" abstract="false" name="EBPParticipantAccountMaximumPlanInvestmentBalancePercent" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="frme_EBPEmployerContributionVestingServiceHours" abstract="false" name="EBPEmployerContributionVestingServiceHours" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="frme_EBPEmployerContributionVestingPercentage" abstract="false" name="EBPEmployerContributionVestingPercentage" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="frme_EBPEmployerContributionVestingServicePeriod" abstract="false" name="EBPEmployerContributionVestingServicePeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="frme_EBPEmployerParticipantServicePeriod" abstract="false" name="EBPEmployerParticipantServicePeriod" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="frme_EBPNoteReceivableFromParticipantGeneralLoanMaximumBorrowingTerm" abstract="false" name="EBPNoteReceivableFromParticipantGeneralLoanMaximumBorrowingTerm" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="frme_EBPChangeInNetAssetAvailableForBenefitIncreaseFromInvestmentFeeRebates" abstract="false" name="EBPChangeInNetAssetAvailableForBenefitIncreaseFromInvestmentFeeRebates" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="frme_EBPInvestmentReconciliationRollForward" abstract="true" name="EBPInvestmentReconciliationRollForward" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="frme_EBPScheduleOfDelinquentParticipantContributionLostEarningsFullyFunded" abstract="false" name="EBPScheduleOfDelinquentParticipantContributionLostEarningsFullyFunded" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
</xs:schema>
