<?xml version="1.0"?><ownershipDocument><schemaVersion>X0201</schemaVersion>    <documentType>4</documentType><periodOfReport>2003-10-20</periodOfReport><notSubjectToSection16>0</notSubjectToSection16><issuer><issuerCik>0000810958</issuerCik><issuerName>CITIZENS &amp; NORTHERN CORP</issuerName>        <issuerTradingSymbol>CZNC.OB</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId><rptOwnerCik>0001242482</rptOwnerCik><rptOwnerName>TYLER ANN M</rptOwnerName></reportingOwnerId><reportingOwnerAddress><rptOwnerStreet1>278 BLUEBIRD LANE</rptOwnerStreet1><rptOwnerStreet2></rptOwnerStreet2><rptOwnerCity>COGAN STATION</rptOwnerCity><rptOwnerState>PA</rptOwnerState><rptOwnerZipCode>17728</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>2003-10-20</value></transactionDate><deemedExecutionDate><value>2003-10-22</value></deemedExecutionDate><transactionCoding><transactionFormType>5</transactionFormType><transactionCode>J</transactionCode><equitySwapInvolved>0</equitySwapInvolved><footnoteId id="F1" /></transactionCoding><transactionTimeliness><value>E</value></transactionTimeliness><transactionAmounts><transactionShares><value>9</value></transactionShares><transactionPricePerShare><value>26</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>1019</value></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></nonDerivativeTransaction></nonDerivativeTable><footnotes><footnote id="F1">Dividend of 10/20/03 posted to D/R Account on 10/22/03</footnote></footnotes><remarks></remarks><ownerSignature><signatureName>Kathleen M. Osgood for Ann M. Tyler under Power of Attorney dated 4/15/02</signatureName><signatureDate>2003-10-30</signatureDate></ownerSignature></ownershipDocument>

