<SUBMISSION>
<ACCESSION-NUMBER>0000719220-04-000039
<TYPE>4/A
<PUBLIC-DOCUMENT-COUNT>2
<PERIOD>20040917
<FILING-DATE>20040921
<DATE-OF-FILING-DATE-CHANGE>20040921
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>ANTOLIK DAVID G
<CIK>0001164377
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4/A
<ACT>34
<FILE-NUMBER>000-12508
<FILM-NUMBER>041038621
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>P.O. BOX 190
<CITY>INDIANA
<STATE>PA
<ZIP>15701
<PHONE>7244657430
</BUSINESS-ADDRESS>
</REPORTING-OWNER>
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>S&T BANCORP INC
<CIK>0000719220
<ASSIGNED-SIC>6022
<IRS-NUMBER>251434426
<STATE-OF-INCORPORATION>PA
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>43 SOUTH NINTH ST
<STREET2>P O BOX 190
<CITY>INDIANA
<STATE>PA
<ZIP>15701
<PHONE>7244651466
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>800 PHILADELPHIA STREET
<CITY>INDIANA
<STATE>PA
<ZIP>15701
</MAIL-ADDRESS>
</ISSUER>
<DOCUMENT>
<TYPE>4/A
<SEQUENCE>1
<FILENAME>doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2004-09-17</periodOfReport>

    <dateOfOriginalSubmission>2004-09-14</dateOfOriginalSubmission>

    <issuer>
        <issuerCik>0000719220</issuerCik>
        <issuerName>S&amp;T BANCORP INC</issuerName>
        <issuerTradingSymbol>STBA</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001164377</rptOwnerCik>
            <rptOwnerName>ANTOLIK DAVID G</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>43 SOUTH NINTH STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>INDIANA</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>15701</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>EXECUTIVE VICE PRESIDENT</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1600</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2004-09-17</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2004-09-17</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>6068.82</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>33.85</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>646</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>401K</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Options (Right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>27.75</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <value>2008-12-21</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
        <derivativeHolding>
            <securityTitle>
                <value>Stock Options (Right to buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>29.965</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2005-01-01</value>
            </exerciseDate>
            <expirationDate>
                <value>2013-12-15</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>6500</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F2">These stock options are granted in December and have a six-month vesting period and a ten year contractural life.</footnote>
        <footnote id="F1">This disposition is to correct the number of shares in the Thrift Plan (401K).</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Wendy S. Bell</signatureName>
        <signatureDate>2004-09-21</signatureDate>
    </ownerSignature>
</ownershipDocument>

</XML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-24
<SEQUENCE>2
<FILENAME>powerofattorney.txt
<DESCRIPTION>POWER OF ATTORNEY LETTER
<TEXT>
This Statement confirms that the undersigned, David G. Antolik,
 has authorized and designated each of Robert E. Rout, Wendy S. Bell or
Timothy P. McKee to execute and file on the undersigned's behalf all Forms
3, 4 and 5 (including any amendments thereto) that the undersigned may be
required to file with the U.S. Securities and Exchange Commission as a result
of the undersigned's ownership of or transactions in securities of S&T Bancorp,
Inc.  The authority of Robert E. Rout, Wendy S. Bell or Timothy P. McKee under
this Statement shall continue until the undersigned is no longer required to
file Forms 3, 4 and 5 with regard to his/her ownership of or transactions in
securities of S&T Bancorp, Inc., unless earlier revoked in writing.  The
undersigned acknowledges that Robert E. Rout, Wendy S. Bell or Timothy P.
McKee are not assuming any of the undersigned's responsibilities to comply
with Section 16 of the Securities Exchange Act of 1934.


/s/ David G. Antolik

</TEXT>
</DOCUMENT>
</SUBMISSION>
