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

<!--XBRL Document Created with Wdesk from Workiva-->
<!--Copyright 2022 Workiva-->
<!--r:b233436c-883a-467d-889a-ddebb7ceb649,g:d398920b-f584-4e00-b6b5-578fe02c3ff3-->
<xs:schema xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:fcf="http://www.fcbanking.com/20220331" xmlns:xbrli="http://www.xbrl.org/2003/instance" xmlns:dtr-types="http://www.xbrl.org/dtr/type/2020-01-21" xmlns:xbrldt="http://xbrl.org/2005/xbrldt" attributeFormDefault="unqualified" elementFormDefault="qualified" targetNamespace="http://www.fcbanking.com/20220331">
  <xs:import namespace="http://fasb.org/srt/2021-01-31" schemaLocation="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd"/>
  <xs:import namespace="http://fasb.org/us-gaap/2021-01-31" schemaLocation="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd"/>
  <xs:import namespace="http://www.w3.org/1999/xlink" schemaLocation="http://www.xbrl.org/2003/xlink-2003-12-31.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/2020-01-21" schemaLocation="https://www.xbrl.org/dtr/type/2020-01-21/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/2021" schemaLocation="https://xbrl.sec.gov/dei/2021/dei-2021.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="fcf-20220331_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="fcf-20220331_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="fcf-20220331_cal.xml" xlink:role="http://www.xbrl.org/2003/role/calculationLinkbaseRef" 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="fcf-20220331_def.xml" xlink:role="http://www.xbrl.org/2003/role/definitionLinkbaseRef" xlink:type="simple"/>
      <link:roleType id="CoverPage" roleURI="http://www.fcbanking.com/role/CoverPage">
        <link:definition>0001001 - Document - Cover Page</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="CondensedConsolidatedStatementsofFinancialConditionUnaudited" roleURI="http://www.fcbanking.com/role/CondensedConsolidatedStatementsofFinancialConditionUnaudited">
        <link:definition>1001002 - Statement - Condensed Consolidated Statements of Financial Condition (Unaudited)</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="CondensedConsolidatedStatementsofIncomeUnaudited" roleURI="http://www.fcbanking.com/role/CondensedConsolidatedStatementsofIncomeUnaudited">
        <link:definition>1002003 - Statement - Condensed Consolidated Statements of Income (Unaudited)</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="CondensedConsolidatedStatementsofComprehensiveIncomeUnaudited" roleURI="http://www.fcbanking.com/role/CondensedConsolidatedStatementsofComprehensiveIncomeUnaudited">
        <link:definition>1003004 - Statement - Condensed Consolidated Statements of Comprehensive Income (Unaudited)</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="CondensedConsolidatedStatementsofChangesinShareholdersEquityUnaudited" roleURI="http://www.fcbanking.com/role/CondensedConsolidatedStatementsofChangesinShareholdersEquityUnaudited">
        <link:definition>1004005 - Statement - Condensed Consolidated Statements of Changes in Shareholders' Equity (Unaudited)</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="CondensedConsolidatedStatementsofCashFlowsUnaudited" roleURI="http://www.fcbanking.com/role/CondensedConsolidatedStatementsofCashFlowsUnaudited">
        <link:definition>1005006 - Statement - Condensed Consolidated Statements of Cash Flows (Unaudited)</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="BasisofPresentation" roleURI="http://www.fcbanking.com/role/BasisofPresentation">
        <link:definition>2101101 - Disclosure - Basis of Presentation</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="SupplementalComprehensiveIncomeDisclosures" roleURI="http://www.fcbanking.com/role/SupplementalComprehensiveIncomeDisclosures">
        <link:definition>2102102 - Disclosure - Supplemental Comprehensive Income Disclosures</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="ComprehensiveIncomeDisclosuresTables" roleURI="http://www.fcbanking.com/role/ComprehensiveIncomeDisclosuresTables">
        <link:definition>2303301 - Disclosure - Comprehensive Income Disclosures (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="ReclassificationofAccumulatedOtherComprehensiveIncomeDetails" roleURI="http://www.fcbanking.com/role/ReclassificationofAccumulatedOtherComprehensiveIncomeDetails">
        <link:definition>2404401 - Disclosure - Reclassification of Accumulated Other Comprehensive Income (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="ScheduleofAccumulatedOtherComprehensiveIncomeDetails" roleURI="http://www.fcbanking.com/role/ScheduleofAccumulatedOtherComprehensiveIncomeDetails">
        <link:definition>2405402 - Disclosure - Schedule of Accumulated Other Comprehensive Income (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="SupplementalCashFlowNote" roleURI="http://www.fcbanking.com/role/SupplementalCashFlowNote">
        <link:definition>2106103 - Disclosure - Supplemental Cash Flow Note</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="SupplementalCashFlowNoteTables" roleURI="http://www.fcbanking.com/role/SupplementalCashFlowNoteTables">
        <link:definition>2307302 - Disclosure - Supplemental Cash Flow Note (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="SupplementalCashFlowDisclosuresNoncashInvestingandFinancingActivitiesDetails" roleURI="http://www.fcbanking.com/role/SupplementalCashFlowDisclosuresNoncashInvestingandFinancingActivitiesDetails">
        <link:definition>2408403 - Disclosure - Supplemental Cash Flow Disclosures - Non-cash Investing and Financing Activities (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="EarningsperShare" roleURI="http://www.fcbanking.com/role/EarningsperShare">
        <link:definition>2109104 - Disclosure - Earnings per Share</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="EarningsperShareTables" roleURI="http://www.fcbanking.com/role/EarningsperShareTables">
        <link:definition>2310303 - Disclosure - Earnings per Share (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="EarningsperShareCompositionofWeightedAverageCommonSharesDenominatorUsedinBasicandDilutedEarningsPerShareDetail" roleURI="http://www.fcbanking.com/role/EarningsperShareCompositionofWeightedAverageCommonSharesDenominatorUsedinBasicandDilutedEarningsPerShareDetail">
        <link:definition>2411404 - Disclosure - Earnings per Share - Composition of Weighted-Average Common Shares (Denominator) Used in Basic and Diluted Earnings Per Share (Detail)</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="EarningsperShareCommonStockEquivalentsNotIncludedinComputationofDilutedEarningsPerShareDetail" roleURI="http://www.fcbanking.com/role/EarningsperShareCommonStockEquivalentsNotIncludedinComputationofDilutedEarningsPerShareDetail">
        <link:definition>2412405 - Disclosure - Earnings per Share - Common Stock Equivalents Not Included in Computation of Diluted Earnings Per Share (Detail)</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="CommitmentsandContingentLiabilities" roleURI="http://www.fcbanking.com/role/CommitmentsandContingentLiabilities">
        <link:definition>2113105 - Disclosure - Commitments and Contingent 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="CommitmentsandContingentLiabilitiesTables" roleURI="http://www.fcbanking.com/role/CommitmentsandContingentLiabilitiesTables">
        <link:definition>2314304 - Disclosure - Commitments and Contingent 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="CommitmentsandContingentLiabilitiesNotionalAmountofOutstandingCommitmentsDetail" roleURI="http://www.fcbanking.com/role/CommitmentsandContingentLiabilitiesNotionalAmountofOutstandingCommitmentsDetail">
        <link:definition>2415406 - Disclosure - Commitments and Contingent Liabilities - Notional Amount of Outstanding Commitments (Detail)</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="CommitmentsandContingentLiabilitiesAdditionalInformationDetail" roleURI="http://www.fcbanking.com/role/CommitmentsandContingentLiabilitiesAdditionalInformationDetail">
        <link:definition>2416407 - Disclosure - Commitments and Contingent Liabilities - Additional Information (Detail)</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="InvestmentSecurities" roleURI="http://www.fcbanking.com/role/InvestmentSecurities">
        <link:definition>2117106 - Disclosure - Investment Securities</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="InvestmentSecuritiesTables" roleURI="http://www.fcbanking.com/role/InvestmentSecuritiesTables">
        <link:definition>2318305 - Disclosure - Investment Securities (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="InvestmentSecuritiesAnalysisofAmortizedCostandEstimatedFairValuesofSecuritiesAvailableforSaleDetail" roleURI="http://www.fcbanking.com/role/InvestmentSecuritiesAnalysisofAmortizedCostandEstimatedFairValuesofSecuritiesAvailableforSaleDetail">
        <link:definition>2419408 - Disclosure - Investment Securities - Analysis of Amortized Cost and Estimated Fair Values of Securities Available for Sale (Detail)</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="InvestmentSecuritiesMaturityofSecuritiesAvailableforSaleDetail" roleURI="http://www.fcbanking.com/role/InvestmentSecuritiesMaturityofSecuritiesAvailableforSaleDetail">
        <link:definition>2420409 - Disclosure - Investment Securities - Maturity of Securities Available for Sale (Detail)</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="InvestmentSecuritiesProceedsfromSaleGrossGainsLossesRealizedonSalesMaturitiesandOtherThanTemporaryImpairmentChargesRelatedtoSecuritiesAvailableforSaleDetail" roleURI="http://www.fcbanking.com/role/InvestmentSecuritiesProceedsfromSaleGrossGainsLossesRealizedonSalesMaturitiesandOtherThanTemporaryImpairmentChargesRelatedtoSecuritiesAvailableforSaleDetail">
        <link:definition>2421410 - Disclosure - Investment Securities - Proceeds from Sale, Gross Gains (Losses) Realized on Sales, Maturities and Other-Than-Temporary Impairment Charges Related to Securities Available for Sale (Detail)</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="InvestmentSecuritiesHeldtoMaturitySecuritiesbyTypeDetails" roleURI="http://www.fcbanking.com/role/InvestmentSecuritiesHeldtoMaturitySecuritiesbyTypeDetails">
        <link:definition>2422411 - Disclosure - Investment Securities Held to Maturity Securities by Type (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="InvestmentSecuritiesScheduleofHeldtoMaturitySecuritiesDetails" roleURI="http://www.fcbanking.com/role/InvestmentSecuritiesScheduleofHeldtoMaturitySecuritiesDetails">
        <link:definition>2423412 - Disclosure - Investment Securities Schedule of Held-to-Maturity Securities (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="ScheduleofTemporaryImpairmentLossesInvestmentsDetails" roleURI="http://www.fcbanking.com/role/ScheduleofTemporaryImpairmentLossesInvestmentsDetails">
        <link:definition>2424413 - Disclosure - Schedule of Temporary Impairment Losses, Investments (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="InvestmentSecuritiesAdditionalInformationDetail" roleURI="http://www.fcbanking.com/role/InvestmentSecuritiesAdditionalInformationDetail">
        <link:definition>2425414 - Disclosure - Investment Securities - Additional Information (Detail)</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="LoansandAllowanceforCreditLosses" roleURI="http://www.fcbanking.com/role/LoansandAllowanceforCreditLosses">
        <link:definition>2126107 - Disclosure - Loans and Allowance for Credit Losses</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="LoansandAllowanceforCreditLossesTables" roleURI="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesTables">
        <link:definition>2327306 - Disclosure - Loans and Allowance for Credit Losses (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="LoansandAllowanceforCreditLossesOutstandingBalancesofLoanDetail" roleURI="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesOutstandingBalancesofLoanDetail">
        <link:definition>2428415 - Disclosure - Loans and Allowance for Credit Losses - Outstanding Balances of Loan (Detail)</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="LoansandAllowanceforCreditLossesCreditRiskProfilebyCreditworthinessDetail" roleURI="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesCreditRiskProfilebyCreditworthinessDetail">
        <link:definition>2429416 - Disclosure - Loans and Allowance for Credit Losses - Credit Risk Profile by Creditworthiness (Detail)</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="LoansandAllowanceforCreditLossesCreditRiskProfileVintagebyCreditworthinessDetails" roleURI="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesCreditRiskProfileVintagebyCreditworthinessDetails">
        <link:definition>2430417 - Disclosure - Loans and Allowance for Credit Losses - Credit Risk Profile Vintage by Creditworthiness (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="LoansandAllowanceforCreditLossesAgeAnalysisofPastDueLoansbySegmentDetail" roleURI="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesAgeAnalysisofPastDueLoansbySegmentDetail">
        <link:definition>2431418 - Disclosure - Loans and Allowance for Credit Losses - Age Analysis of Past Due Loans by Segment (Detail)</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="LoansandAllowanceforCreditLossesRecordedInvestmentandUnpaidPrincipalBalanceforImpairedLoanswithAssociatedAllowanceDetail" roleURI="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesRecordedInvestmentandUnpaidPrincipalBalanceforImpairedLoanswithAssociatedAllowanceDetail">
        <link:definition>2432419 - Disclosure - Loans and Allowance for Credit Losses - Recorded Investment and Unpaid Principal Balance for Impaired Loans with Associated Allowance (Detail)</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="LoansandAllowanceforCreditLossesTroubledDebtRestructuredLoansandCommitmentsDetail" roleURI="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesTroubledDebtRestructuredLoansandCommitmentsDetail">
        <link:definition>2433420 - Disclosure - Loans and Allowance for Credit Losses - Troubled Debt Restructured Loans and Commitments (Detail)</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="LoansandAllowanceforCreditLossesTroubledDebtRestructuringsIdentifiedDuringPeriodDetail" roleURI="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesTroubledDebtRestructuringsIdentifiedDuringPeriodDetail">
        <link:definition>2434421 - Disclosure - Loans and Allowance for Credit Losses - Troubled Debt Restructurings Identified During Period (Detail)</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="LoansandAllowanceforCreditLossesTroubledDebtRestructuringis90DaysorMorePastDueDetail" roleURI="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesTroubledDebtRestructuringis90DaysorMorePastDueDetail">
        <link:definition>2435422 - Disclosure - Loans and Allowance for Credit Losses - Troubled Debt Restructuring is 90 Days or More Past Due (Detail)</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="LoansandAllowanceforCreditLossesAllowanceforCreditLossesDetail" roleURI="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesAllowanceforCreditLossesDetail">
        <link:definition>2436423 - Disclosure - Loans and Allowance for Credit Losses - Allowance for Credit Losses (Detail)</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="LoansandAllowanceforCreditLossesAdditionalInformationDetail" roleURI="http://www.fcbanking.com/role/LoansandAllowanceforCreditLossesAdditionalInformationDetail">
        <link:definition>2437424 - Disclosure - Loans and Allowance for Credit Losses - Additional Information (Detail)</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="LeasesLeases" roleURI="http://www.fcbanking.com/role/LeasesLeases">
        <link:definition>2138108 - Disclosure - Leases Leases</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="LeasesLeaseLiabilityMaturityTables" roleURI="http://www.fcbanking.com/role/LeasesLeaseLiabilityMaturityTables">
        <link:definition>2339307 - Disclosure - Leases Lease Liability Maturity (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="LeasesOperatingLeaseAssetsandLiabilitiesDetails" roleURI="http://www.fcbanking.com/role/LeasesOperatingLeaseAssetsandLiabilitiesDetails">
        <link:definition>2440425 - Disclosure - Leases Operating Lease 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="LeasesLeaseLiablityMaturityDetails" roleURI="http://www.fcbanking.com/role/LeasesLeaseLiablityMaturityDetails">
        <link:definition>2441426 - Disclosure - Leases Lease Liablity Maturity (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="IncomeTaxes" roleURI="http://www.fcbanking.com/role/IncomeTaxes">
        <link:definition>2142109 - Disclosure - Income Taxes</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="IncomeTaxesDetails" roleURI="http://www.fcbanking.com/role/IncomeTaxesDetails">
        <link:definition>2443427 - Disclosure - Income Taxes (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="FairValuesofAssetsandLiabilities" roleURI="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilities">
        <link:definition>2144110 - Disclosure - Fair Values 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="FairValuesofAssetsandLiabilitiesTables" roleURI="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilitiesTables">
        <link:definition>2345308 - Disclosure - Fair Values 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="FairValuesofAssetsandLiabilitiesQuantitativeInputsandAssumptionsUsedinLevel3FairValueMeasurementsDetail" roleURI="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilitiesQuantitativeInputsandAssumptionsUsedinLevel3FairValueMeasurementsDetail">
        <link:definition>2446428 - Disclosure - Fair Values of Assets and Liabilities - Quantitative Inputs and Assumptions Used in Level 3 Fair Value Measurements (Detail)</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="FairValuesofAssetsandLiabilitiesScheduleofAssetsandLiabilitiesMeasuredatFairValueonRecurringBasisDetail" roleURI="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilitiesScheduleofAssetsandLiabilitiesMeasuredatFairValueonRecurringBasisDetail">
        <link:definition>2447429 - Disclosure - Fair Values of Assets and Liabilities - Schedule of Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail)</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="FairValuesofAssetsandLiabilitiesScheduleofChangesinLevel3AssetsandLiabilitiesMeasuredatFairValueonRecurringBasisDetail" roleURI="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilitiesScheduleofChangesinLevel3AssetsandLiabilitiesMeasuredatFairValueonRecurringBasisDetail">
        <link:definition>2448430 - Disclosure - Fair Values of Assets and Liabilities - Schedule of Changes in Level 3 Assets and Liabilities Measured at Fair Value on Recurring Basis (Detail)</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="FairValuesofAssetsandLiabilitiesScheduleofAssetsMeasuredonNonRecurringBasisDetail" roleURI="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilitiesScheduleofAssetsMeasuredonNonRecurringBasisDetail">
        <link:definition>2449431 - Disclosure - Fair Values of Assets and Liabilities - Schedule of Assets Measured on Non-Recurring Basis (Detail)</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="FairValuesofAssetsandLiabilitiesLossesRealizedonAssetsMeasuredonNonRecurringBasisDetail" roleURI="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilitiesLossesRealizedonAssetsMeasuredonNonRecurringBasisDetail">
        <link:definition>2450432 - Disclosure - Fair Values of Assets and Liabilities - Losses Realized on Assets Measured on Non-Recurring Basis (Detail)</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="FairValuesofAssetsandLiabilitiesCarryingAmountsandFairValuesofFinancialInstrumentsDetail" roleURI="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilitiesCarryingAmountsandFairValuesofFinancialInstrumentsDetail">
        <link:definition>2451433 - Disclosure - Fair Values of Assets and Liabilities - Carrying Amounts and Fair Values of Financial Instruments (Detail)</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="FairValuesofAssetsandLiabilitiesAdditionalInformationDetail" roleURI="http://www.fcbanking.com/role/FairValuesofAssetsandLiabilitiesAdditionalInformationDetail">
        <link:definition>2452434 - Disclosure - Fair Values of Assets and Liabilities - Additional Information (Detail)</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="Derivatives" roleURI="http://www.fcbanking.com/role/Derivatives">
        <link:definition>2153111 - Disclosure - Derivatives</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="DerivativesTables" roleURI="http://www.fcbanking.com/role/DerivativesTables">
        <link:definition>2354309 - Disclosure - Derivatives (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="DerivativesAdditionalInformationDetail" roleURI="http://www.fcbanking.com/role/DerivativesAdditionalInformationDetail">
        <link:definition>2455435 - Disclosure - Derivatives - Additional Information (Detail)</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="DerivativesCreditValueAdjustmentRecordedRelatedtoNotionalAmountofDerivativesOutstandingDetail" roleURI="http://www.fcbanking.com/role/DerivativesCreditValueAdjustmentRecordedRelatedtoNotionalAmountofDerivativesOutstandingDetail">
        <link:definition>2456436 - Disclosure - Derivatives - Credit Value Adjustment Recorded Related to Notional Amount of Derivatives Outstanding (Detail)</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="DerivativesScheduleofChangesinFairValueofDerivativeAssetsandLiabilitiesDetail" roleURI="http://www.fcbanking.com/role/DerivativesScheduleofChangesinFairValueofDerivativeAssetsandLiabilitiesDetail">
        <link:definition>2457437 - Disclosure - Derivatives - Schedule of Changes in Fair Value of Derivative Assets and Liabilities (Detail)</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="Goodwill" roleURI="http://www.fcbanking.com/role/Goodwill">
        <link:definition>2158112 - Disclosure - Goodwill</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="GoodwillAdditionalInformationDetail" roleURI="http://www.fcbanking.com/role/GoodwillAdditionalInformationDetail">
        <link:definition>2459438 - Disclosure - Goodwill - Additional Information (Detail)</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="SubordinatedDebenturesSubordinatedDebenturesOutstanding" roleURI="http://www.fcbanking.com/role/SubordinatedDebenturesSubordinatedDebenturesOutstanding">
        <link:definition>2160113 - Disclosure - Subordinated Debentures Subordinated Debentures Outstanding</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="SubordinatedDebenturesSubordinatedDebenturesOutstandingTables" roleURI="http://www.fcbanking.com/role/SubordinatedDebenturesSubordinatedDebenturesOutstandingTables">
        <link:definition>2361310 - Disclosure - Subordinated Debentures Subordinated Debentures Outstanding (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="SubordinatedDebenturesScheduleofSubordinatedDebenturesOutstandingDetails" roleURI="http://www.fcbanking.com/role/SubordinatedDebenturesScheduleofSubordinatedDebenturesOutstandingDetails">
        <link:definition>2462439 - Disclosure - Subordinated Debentures Schedule of Subordinated Debentures Outstanding (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="SubordinatedDebenturesSubordinatedDebenturesAdditionalInformationDetails" roleURI="http://www.fcbanking.com/role/SubordinatedDebenturesSubordinatedDebenturesAdditionalInformationDetails">
        <link:definition>2463440 - Disclosure - Subordinated Debentures Subordinated Debentures, Additional Information (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="RevenueRecognitionandDeferredRevenue" roleURI="http://www.fcbanking.com/role/RevenueRecognitionandDeferredRevenue">
        <link:definition>2164114 - Disclosure - Revenue Recognition and Deferred Revenue</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="RevenueRecognitionRevenueRecogntionTables" roleURI="http://www.fcbanking.com/role/RevenueRecognitionRevenueRecogntionTables">
        <link:definition>2365311 - Disclosure - Revenue Recognition Revenue Recogntion (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="RevenueRecognitionInScopeandOutofScopeRevenueStreamsDetails" roleURI="http://www.fcbanking.com/role/RevenueRecognitionInScopeandOutofScopeRevenueStreamsDetails">
        <link:definition>2466441 - Disclosure - Revenue Recognition In-Scope and Out-of-Scope Revenue Streams (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="RevenueRecognitionRevenueRecognitionDetails" roleURI="http://www.fcbanking.com/role/RevenueRecognitionRevenueRecognitionDetails">
        <link:definition>2467442 - Disclosure - Revenue Recognition Revenue Recognition (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="fcf_SubordinatedDebenturesOutstandingAbstract" abstract="true" name="SubordinatedDebenturesOutstandingAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="fcf_SubordinatedDebtParAmount" abstract="false" name="SubordinatedDebtParAmount" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_FairValueWeightedAverageInputsPrice" abstract="false" name="FairValueWeightedAverageInputsPrice" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_NotionalAmountOfPerformanceStandbyLettersOfCredit" abstract="false" name="NotionalAmountOfPerformanceStandbyLettersOfCredit" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_OwnerOccupiedCommercialRealEstateMember" abstract="true" name="OwnerOccupiedCommercialRealEstateMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_USGovernmentAgencyDebtSecuritiesResidentialDomain" abstract="true" name="USGovernmentAgencyDebtSecuritiesResidentialDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_BranchConsolidationExpenses" abstract="false" name="BranchConsolidationExpenses" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_ChargeoffsDomain" abstract="true" name="ChargeoffsDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_NetDeferredFeesMember" abstract="true" name="NetDeferredFeesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_InvestmentSecuritiesContinuousUnrealizedLossPositionLessthan12MonthsAccumulatedLoss" abstract="false" name="InvestmentSecuritiesContinuousUnrealizedLossPositionLessthan12MonthsAccumulatedLoss" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_InvestmentSecuritiesContinuousUnrealizedLossPositionLessthanTwelveMonthsFairValue" abstract="false" name="InvestmentSecuritiesContinuousUnrealizedLossPositionLessthanTwelveMonthsFairValue" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_InvestmentSecuritiesContinuousUnrealizedLossPosition12MonthsorLongerAccumulatedLoss" abstract="false" name="InvestmentSecuritiesContinuousUnrealizedLossPosition12MonthsorLongerAccumulatedLoss" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_GoodwillDisclosureAbstract" abstract="true" name="GoodwillDisclosureAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="fcf_GrossIncreaseInMarketValueAdjustmentToSecuritiesAvailableForSale" abstract="false" name="GrossIncreaseInMarketValueAdjustmentToSecuritiesAvailableForSale" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_NonownerOccupiedCommercialRealEstateMember" abstract="true" name="NonownerOccupiedCommercialRealEstateMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_GrossIncreaseinMarketValueAdjustmenttoDerivatives" abstract="false" name="GrossIncreaseinMarketValueAdjustmenttoDerivatives" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_RiskparticipationAgreementsTable" abstract="true" name="RiskparticipationAgreementsTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="fcf_OtherConsumerLoansMember" abstract="true" name="OtherConsumerLoansMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_FirstCommonwealthBank2028Member" abstract="true" name="FirstCommonwealthBank2028Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_NonaccrualLoansPaidOffAxis" abstract="true" name="NonaccrualLoansPaidOffAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="fcf_LoansTransferredtoOtherRealEstateOwnedandRepossessions" abstract="false" name="LoansTransferredtoOtherRealEstateOwnedandRepossessions" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_ReserveForOffBalanceSheetActivities" abstract="false" name="ReserveForOffBalanceSheetActivities" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_IncentiveRevenue" abstract="false" name="IncentiveRevenue" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_UnearnedPremiumsAndDiscountsMember" abstract="true" name="UnearnedPremiumsAndDiscountsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_RiskParticipationAgreementsDomain" abstract="true" name="RiskParticipationAgreementsDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_FairValueInputDiscountRate" abstract="false" name="FairValueInputDiscountRate" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="fcf_USGovernmentAgenciesDebtSecuritiesCommercialMember" abstract="true" name="USGovernmentAgenciesDebtSecuritiesCommercialMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_UnsettledBankOwnedLifeInsuranceProceeds" abstract="false" name="UnsettledBankOwnedLifeInsuranceProceeds" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_LoansWithModificationsToRateAndPaymentDueToReamortization" abstract="false" name="LoansWithModificationsToRateAndPaymentDueToReamortization" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_FinancingReceivableTroubledDebtRestructuringsLineItemsLineItems" abstract="true" name="FinancingReceivableTroubledDebtRestructuringsLineItemsLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="fcf_ScopeofTopic606Axis" abstract="true" name="ScopeofTopic606Axis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="fcf_RiskParticipationAgreementsAxis" abstract="true" name="RiskParticipationAgreementsAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="fcf_CreditValueAdjustmentRecordedRelatedToNotionalAmountOfDerivativesOutstandingTableTextBlock" abstract="false" name="CreditValueAdjustmentRecordedRelatedToNotionalAmountOfDerivativesOutstandingTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="fcf_CommercialLettersOfCreditMember" abstract="true" name="CommercialLettersOfCreditMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_DiscountRatesMember" abstract="true" name="DiscountRatesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_ScheduleOfRecordedInvestmentAndUnpaidPrincipalBalanceForImpairedLoansWithAssociatedAllowanceTableTextBlock" abstract="false" name="ScheduleOfRecordedInvestmentAndUnpaidPrincipalBalanceForImpairedLoansWithAssociatedAllowanceTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="fcf_NonAccrualStatusOfLoansAfterNumberOfDaysPastDue" abstract="false" name="NonAccrualStatusOfLoansAfterNumberOfDaysPastDue" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="fcf_LoanToDifferentProjectAxis" abstract="true" name="LoanToDifferentProjectAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="fcf_FairValueMeasurementOfAssetsOnNonrecurringBasisNetLoss" abstract="false" name="FairValueMeasurementOfAssetsOnNonrecurringBasisNetLoss" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_ConsumerCreditCardsMember" abstract="true" name="ConsumerCreditCardsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_NotionalAmountOfCommercialLettersOfCredit" abstract="false" name="NotionalAmountOfCommercialLettersOfCredit" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_GasperMMBTUMember" abstract="true" name="GasperMMBTUMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_InterestRateCollarMember" abstract="true" name="InterestRateCollarMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_AccrualLoansMember" abstract="true" name="AccrualLoansMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_InvestmentSecuritiesTable" abstract="true" name="InvestmentSecuritiesTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="fcf_InScopeandOutofScopeRevenueAbstract" abstract="true" name="InScopeandOutofScopeRevenueAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="fcf_LimitedPartnershipInvestmentMember" abstract="true" name="LimitedPartnershipInvestmentMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_ScheduleofHeldtoMaturitySecuritiesbyMaturityTableTextBlock" abstract="false" name="ScheduleofHeldtoMaturitySecuritiesbyMaturityTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="fcf_IncreaseInCashSurrenderValueofBOLI" abstract="false" name="IncreaseInCashSurrenderValueofBOLI" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_RevolvingLoansReceivableMember" abstract="true" name="RevolvingLoansReceivableMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_NotionalAmountOfCommitmentsAndLettersOfCredit" abstract="false" name="NotionalAmountOfCommitmentsAndLettersOfCredit" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_ScheduleOfUnrealizedLossesAndEstimatedFairValuesLineItems" abstract="true" name="ScheduleOfUnrealizedLossesAndEstimatedFairValuesLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="fcf_ThreeYearOriginalMaturityMember" abstract="true" name="ThreeYearOriginalMaturityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_TermLoanReceivableOriginatedFiveOrMoreYearsPriorMember" abstract="true" name="TermLoanReceivableOriginatedFiveOrMoreYearsPriorMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_TermLoanReceivableOriginatedThreeYearsPriorMember" abstract="true" name="TermLoanReceivableOriginatedThreeYearsPriorMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_FirstCommonwealthCapitalTrustIIIMember" abstract="true" name="FirstCommonwealthCapitalTrustIIIMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_NotionalAmountOfFinancialStandbyLettersOfCredit" abstract="false" name="NotionalAmountOfFinancialStandbyLettersOfCredit" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_IncreasesinNonperformingLoansDomain" abstract="true" name="IncreasesinNonperformingLoansDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_ImpairedLoansMember" abstract="true" name="ImpairedLoansMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_InvestmentSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss" abstract="false" name="InvestmentSecuritiesContinuousUnrealizedLossPositionAccumulatedLoss" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_NetGainsAndImpairment" abstract="false" name="NetGainsAndImpairment" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_USGovernmentAgencyDebtSecuritiesCommercialMember" abstract="true" name="USGovernmentAgencyDebtSecuritiesCommercialMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_PartofLoanRelationshipDomain" abstract="true" name="PartofLoanRelationshipDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_FiveYearOriginalMaturityMember" abstract="true" name="FiveYearOriginalMaturityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_LoansAndLeasesReceivablePaycheckProtectionProgram" abstract="false" name="LoansAndLeasesReceivablePaycheckProtectionProgram" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_ReserveStudyMember" abstract="true" name="ReserveStudyMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_FairValueMeasurementOfAssetsOnNonrecurringBasisNetLossesOnImpairedLoans" abstract="false" name="FairValueMeasurementOfAssetsOnNonrecurringBasisNetLossesOnImpairedLoans" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_InvestmentSecuritiesContinuousUnrealizedLossPositionTwelveMonthsorLongerFairValue" abstract="false" name="InvestmentSecuritiesContinuousUnrealizedLossPositionTwelveMonthsorLongerFairValue" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_TroubledDebtRestructuringSubsequentDefaultTableTextBlock" abstract="false" name="TroubledDebtRestructuringSubsequentDefaultTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="fcf_IncreasesDecreasesinTroubledDebtRestructuringsAxis" abstract="true" name="IncreasesDecreasesinTroubledDebtRestructuringsAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="fcf_DerivativeLiabilityNotionalAmountGrossAsset" abstract="false" name="DerivativeLiabilityNotionalAmountGrossAsset" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_UnusedCommitmentsDomain" abstract="true" name="UnusedCommitmentsDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_DerivativeFeeIncome" abstract="false" name="DerivativeFeeIncome" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_UnfundedCommitmentsRelatedToNonperformingLoans" abstract="false" name="UnfundedCommitmentsRelatedToNonperformingLoans" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_InvestmentSecuritiesinUnrealizedLossPositionQualitativeDisclosureNumberofPositionsTotal" abstract="false" name="InvestmentSecuritiesinUnrealizedLossPositionQualitativeDisclosureNumberofPositionsTotal" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="xbrli:integerItemType"/>
  <xs:element id="fcf_OilPerBbldMember" abstract="true" name="OilPerBbldMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_ScheduleOfUnrealizedLossesAndEstimatedFairValuesTable" abstract="true" name="ScheduleOfUnrealizedLossesAndEstimatedFairValuesTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="fcf_FinancingReceivableNewTroubledDebtRestructuringTableTextBlock" abstract="false" name="FinancingReceivableNewTroubledDebtRestructuringTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="fcf_InScopeofTopic606Member" abstract="true" name="InScopeofTopic606Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_TimeAndDemandLoansOtherMember" abstract="true" name="TimeAndDemandLoansOtherMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_FourYearOiriginalMaturityMember" abstract="true" name="FourYearOiriginalMaturityMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_OffBalanceSheetReserveToNonperformingLoans" abstract="false" name="OffBalanceSheetReserveToNonperformingLoans" nillable="true" xbrli:periodType="instant" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_PercentOfUnrealizedLosses" abstract="false" name="PercentOfUnrealizedLosses" nillable="true" xbrli:periodType="instant" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="fcf_FairValueMeasurementsOfFinancialInstrumentsTable" abstract="true" name="FairValueMeasurementsOfFinancialInstrumentsTable" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:hypercubeItem" type="xbrli:stringItemType"/>
  <xs:element id="fcf_RestrictedStockUnitsMember" abstract="true" name="RestrictedStockUnitsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_InterestRateMacroSwapMember" abstract="true" name="InterestRateMacroSwapMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_DerivativeLiabilityCostBasisGrossAsset" abstract="false" name="DerivativeLiabilityCostBasisGrossAsset" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_InvestmentSecuritiesAbstract" abstract="true" name="InvestmentSecuritiesAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="fcf_DefaultStatusOfTDRsAfterNumberOfDaysPastDue" abstract="false" name="DefaultStatusOfTDRsAfterNumberOfDaysPastDue" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:durationItemType"/>
  <xs:element id="fcf_TermLoanReceivableOriginatedTwoYearsPriorMember" abstract="true" name="TermLoanReceivableOriginatedTwoYearsPriorMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_InvestmentSecuritiesContinuousUnrealizedLossPositionFairValueTotal" abstract="false" name="InvestmentSecuritiesContinuousUnrealizedLossPositionFairValueTotal" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_ConstructionResidentialMember" abstract="true" name="ConstructionResidentialMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_NonperformingLoansAxis" abstract="true" name="NonperformingLoansAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="fcf_CashPaidForInterestAndIncomeTaxesAbstract" abstract="true" name="CashPaidForInterestAndIncomeTaxesAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="fcf_WeightedAverageNumberofSharesDeferredCompensationPlans" abstract="false" name="WeightedAverageNumberofSharesDeferredCompensationPlans" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="fcf_ImpairedLoansFairValueNonCollection" abstract="false" name="ImpairedLoansFairValueNonCollection" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_ForecastedValueNationalUnemploymentPercent" abstract="false" name="ForecastedValueNationalUnemploymentPercent" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:percentItemType"/>
  <xs:element id="fcf_A2026Member" abstract="true" name="A2026Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_EquipmentFinanceMember" abstract="true" name="EquipmentFinanceMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_ConstructionOtherMember" abstract="true" name="ConstructionOtherMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_DocumentAndEntityInformationAbstract" abstract="true" name="DocumentAndEntityInformationAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="fcf_FirstCommonwealthBank2033Member" abstract="true" name="FirstCommonwealthBank2033Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_LoanToDifferentProjectDomain" abstract="true" name="LoanToDifferentProjectDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_FinancingReceivableTroubledDebtRestructuringSpecificReserve" abstract="false" name="FinancingReceivableTroubledDebtRestructuringSpecificReserve" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_TimeAndDemandLoansMember" abstract="true" name="TimeAndDemandLoansMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_InvestmentSecuritiesLineItems" abstract="true" name="InvestmentSecuritiesLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="fcf_TermLoanReceivableOriginatedInOneYearPriorMember" abstract="true" name="TermLoanReceivableOriginatedInOneYearPriorMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_SubordinatedDebenturesAdditionalInformationAbstract" abstract="true" name="SubordinatedDebenturesAdditionalInformationAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="fcf_COVID19RelatedExpenses" abstract="false" name="COVID19RelatedExpenses" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_CommercialCreditCardsMember" abstract="true" name="CommercialCreditCardsMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_FairValueMeasurementOfAssetsOnNonrecurringBasisNetLossesOnOtherRealEstateOwned" abstract="false" name="FairValueMeasurementOfAssetsOnNonrecurringBasisNetLossesOnOtherRealEstateOwned" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_WeightedAverageNumberOfAdditionalSharesDeferredCompensationPlan" abstract="false" name="WeightedAverageNumberOfAdditionalSharesDeferredCompensationPlan" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:sharesItemType"/>
  <xs:element id="fcf_RiskParticipationAgreementsSoldDomain" abstract="true" name="RiskParticipationAgreementsSoldDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_RiskparticipationAgreementsLineItems" abstract="true" name="RiskparticipationAgreementsLineItems" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="fcf_ChargeoffsAxis" abstract="true" name="ChargeoffsAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="fcf_OperationalLoss" abstract="false" name="OperationalLoss" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_SubordinatedDebenturesAbstract" abstract="true" name="SubordinatedDebenturesAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="fcf_TermLoanReceivableOriginatedInCurrentYearMember" abstract="true" name="TermLoanReceivableOriginatedInCurrentYearMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_PartofLoanRelationshipAxis" abstract="true" name="PartofLoanRelationshipAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="fcf_FeesandCommissionsonDepositorAccounts" abstract="false" name="FeesandCommissionsonDepositorAccounts" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_AdditionalInformationAbstract" abstract="true" name="AdditionalInformationAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="fcf_CreditRiskProfileVintageByCreditworthinessTableTextBlock" abstract="false" name="CreditRiskProfileVintageByCreditworthinessTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="fcf_OtherRealEstateOwnedAssetsFairValue" abstract="false" name="OtherRealEstateOwnedAssetsFairValue" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_NonaccrualCommercialLoansAxis" abstract="true" name="NonaccrualCommercialLoansAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="fcf_OutOfScopeofTopic606Member" abstract="true" name="OutOfScopeofTopic606Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_ContractMaturityAxis" abstract="true" name="ContractMaturityAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="fcf_NonaccrualLoansPaidOffDomain" abstract="true" name="NonaccrualLoansPaidOffDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_UpdatedAppraisalRequirementFloor" abstract="false" name="UpdatedAppraisalRequirementFloor" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_TermLoanReceivableOriginatedFourYearsPriorMember" abstract="true" name="TermLoanReceivableOriginatedFourYearsPriorMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_DerivativeInstrumentsDesignatedAsHedgingInstrumentsInterestExpense" abstract="false" name="DerivativeInstrumentsDesignatedAsHedgingInstrumentsInterestExpense" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_GrossLosses" abstract="false" name="GrossLosses" nillable="true" xbrli:periodType="duration" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_GrossGains" abstract="false" name="GrossGains" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_ContractualPaymentModificationMember" abstract="true" name="ContractualPaymentModificationMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_MaturitiesAndImpairmentAbstract" abstract="true" name="MaturitiesAndImpairmentAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="fcf_UnusedCommitmentsAxis" abstract="true" name="UnusedCommitmentsAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="fcf_GainLossOnSecuritiesAndOtherAssets" abstract="false" name="GainLossOnSecuritiesAndOtherAssets" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_DerivativeInstrumentsDesignatedAsHedgingInstrumentsInterestIncome" abstract="false" name="DerivativeInstrumentsDesignatedAsHedgingInstrumentsInterestIncome" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_ContractMaturityDomain" abstract="true" name="ContractMaturityDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_InterestRateSwapMemberDebtMember" abstract="true" name="InterestRateSwapMemberDebtMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_IncreasesDecreasesinNonperformingLoansAxis" abstract="true" name="IncreasesDecreasesinNonperformingLoansAxis" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrldt:dimensionItem" type="xbrli:stringItemType"/>
  <xs:element id="fcf_ScopeofTopic606Domain" abstract="true" name="ScopeofTopic606Domain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_GainLossesMaturitiesAndImpairment" abstract="false" name="GainLossesMaturitiesAndImpairment" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_LossesRealizedOnAssetsMeasuredOnNonrecurringBasisTableTextBlock" abstract="false" name="LossesRealizedOnAssetsMeasuredOnNonrecurringBasisTableTextBlock" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:textBlockItemType"/>
  <xs:element id="fcf_NonaccrualCommercialLoansMember" abstract="true" name="NonaccrualCommercialLoansMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_CorporateSecuritiesMember" abstract="true" name="CorporateSecuritiesMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_NonAccrualLoansMember" abstract="true" name="NonAccrualLoansMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_FirstCommonwealthCapitalTrustIIMember" abstract="true" name="FirstCommonwealthCapitalTrustIIMember" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_NonaccrualCommercialLoansDomain" abstract="true" name="NonaccrualCommercialLoansDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_NonperformingLoansDomain" abstract="true" name="NonperformingLoansDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_A2024Member" abstract="true" name="A2024Member" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_RiskParticipationAgreementsPurchasedDomain" abstract="true" name="RiskParticipationAgreementsPurchasedDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
  <xs:element id="fcf_FeesandCommissionsonTrustandFiduciaryAccounts" abstract="false" name="FeesandCommissionsonTrustandFiduciaryAccounts" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_SupplementalComprehensiveIncomeDisclosuresAbstract" abstract="true" name="SupplementalComprehensiveIncomeDisclosuresAbstract" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="xbrli:stringItemType"/>
  <xs:element id="fcf_FeesandCommissionsonDebitCards" abstract="false" name="FeesandCommissionsonDebitCards" nillable="true" xbrli:periodType="duration" xbrli:balance="credit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_ImpairedLoansFairValue" abstract="false" name="ImpairedLoansFairValue" nillable="true" xbrli:periodType="instant" xbrli:balance="debit" substitutionGroup="xbrli:item" type="xbrli:monetaryItemType"/>
  <xs:element id="fcf_IncreasesDecreasesinTroubledDebtRestructuringsDomain" abstract="true" name="IncreasesDecreasesinTroubledDebtRestructuringsDomain" nillable="true" xbrli:periodType="duration" substitutionGroup="xbrli:item" type="dtr-types:domainItemType"/>
</xs:schema>
</XBRL>