<?xml version="1.0"?><ownershipDocument><schemaVersion>X0201</schemaVersion>    <documentType>4</documentType><periodOfReport>2003-08-05</periodOfReport><notSubjectToSection16>0</notSubjectToSection16><issuer><issuerCik>0000092081</issuerCik><issuerName>SOUTHTRUST CORP</issuerName>        <issuerTradingSymbol>SOTR</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId><rptOwnerCik>0001192005</rptOwnerCik><rptOwnerName>RICHEY VAN L</rptOwnerName></reportingOwnerId><reportingOwnerAddress><rptOwnerStreet1>POST OFFICE BOX 2727</rptOwnerStreet1><rptOwnerStreet2></rptOwnerStreet2><rptOwnerCity>BIRMINGHAM</rptOwnerCity><rptOwnerState>AL</rptOwnerState><rptOwnerZipCode>35202-2727</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>2003-08-01</value></transactionDate><transactionCoding><transactionFormType>4</transactionFormType><transactionCode>P</transactionCode><equitySwapInvolved>0</equitySwapInvolved></transactionCoding><transactionTimeliness><value></value></transactionTimeliness><transactionAmounts><transactionShares><value>364.292</value></transactionShares><transactionPricePerShare><value>28.3083</value></transactionPricePerShare><transactionAcquiredDisposedCode><value>A</value></transactionAcquiredDisposedCode></transactionAmounts><postTransactionAmounts><sharesOwnedFollowingTransaction><value>20838.819</value><footnoteId id="F1" /></sharesOwnedFollowingTransaction></postTransactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership></ownershipNature></nonDerivativeTransaction></nonDerivativeTable><footnotes><footnote id="F1">Includes 214.815 shares acquired in an exempt transaction pursuant to the dividend reinvestment plan as of 07/01/03.</footnote></footnotes><remarks></remarks><ownerSignature><signatureName>John D. Buchanan - Attorney-in-fact</signatureName><signatureDate>2003-08-05</signatureDate></ownerSignature></ownershipDocument>

