<?xml version="1.0"?><ownershipDocument>
    <schemaVersion>X0201</schemaVersion>

    <documentType>4</documentType><periodOfReport>2003-11-25</periodOfReport><notSubjectToSection16>0</notSubjectToSection16>
    <issuer>
        <issuerCik>0000354869</issuerCik>
        <issuerName>FIRSTMERIT CORP /OH/</issuerName>
        <issuerTradingSymbol>FMER</issuerTradingSymbol></issuer><reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001231621</rptOwnerCik>
            <rptOwnerName>BLICKLE JOHN C</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>III CASCADE PLAZA</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>AKRON</rptOwnerCity>
            <rptOwnerState>OH</rptOwnerState>
            <rptOwnerZipCode>44308</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
            <reportingOwnerRelationship>
<isDirector>1</isDirector><isOfficer>0</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther></reportingOwnerRelationship></reportingOwner><nonDerivativeTable><nonDerivativeTransaction><securityTitle><value>Common Stock</value></securityTitle><transactionDate><value>2003-11-25</value></transactionDate><deemedExecutionDate></deemedExecutionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>J</transactionCode><equitySwapInvolved>0</equitySwapInvolved><footnoteId id="F1" /></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>356.0220</value></transactionShares><transactionPricePerShare><value>27.6200</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>37212.9150</value><footnoteId id="F2" /></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>I</value></directOrIndirectOwnership><natureOfOwnership><value>by Managed Account</value><footnoteId id="F3" /></natureOfOwnership></ownershipNature></nonDerivativeTransaction></nonDerivativeTable><footnotes><footnote id="F1">Allocated to the reporting person's account under FirstMerit Corporation Director Deferred Compensation Plan.</footnote><footnote id="F2">Reporting person also holds 27,260.00 directly, 2,152.00 indirectly, by spouse and 1,100.00 by a related corporation.</footnote><footnote id="F3">Shares in reporting person's account under FirstMerit Corporation Director Deferred Compensation Plan.</footnote></footnotes><remarks></remarks><ownerSignature><signatureName>By:  Terry E. Patton
For:  John C. Blickle</signatureName><signatureDate>2003-11-25</signatureDate></ownerSignature></ownershipDocument>

