<SUBMISSION>
<ACCESSION-NUMBER>0000945094-04-000724
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20041201
<FILING-DATE>20041202
<DATE-OF-FILING-DATE-CHANGE>20041202
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>TAYLOR MARY ALICE
<CIK>0001088860
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-11840
<FILM-NUMBER>041180441
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>3800 CITIBANK CENTER TAMPA
<STREET2>MAIL DROP A/3/1
<CITY>TAMPA
<STATE>FL
<ZIP>33613
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>DELL COMPUTER CORP
<STREET2>ONE DELL WAY
<CITY>ROUND ROCK
<STATE>TX
<ZIP>78682
</MAIL-ADDRESS>
</REPORTING-OWNER>
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>ALLSTATE CORP
<CIK>0000899051
<ASSIGNED-SIC>6331
<IRS-NUMBER>363871531
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>2775 SANDERS ROAD
<CITY>NORTHBROOK
<STATE>IL
<ZIP>60062
<PHONE>8474025000
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>2775 SANDERS ROAD
<CITY>NORTHBROOK
<STATE>IL
<ZIP>60062
</MAIL-ADDRESS>
</ISSUER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>c0001088860d20041202f4f.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-12-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000899051</issuerCik>
        <issuerName>ALLSTATE CORP</issuerName>
        <issuerTradingSymbol>ALL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001088860</rptOwnerCik>
            <rptOwnerName>TAYLOR MARY ALICE</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>6021 PINE GROVE STREET</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>POINT CLEAR</rptOwnerCity>
            <rptOwnerState>AL</rptOwnerState>
            <rptOwnerZipCode>36564</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2004-12-01</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>2000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F1"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>2000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Restricted Stock Units (RSUs) are granted under The Allstate Corporation Equity Incentive Plan for Non-Employee Directors, as Amended and Restated effective as of November 9, 2004.  Each RSU represents the right to receive one share of Allstate common stock upon the earlier of (i) the date of the reporting person's death or disability, and (ii) one year after the date on which the reporting person is no longer serving as a director of Allstate.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>MARY ALICE  TAYLOR</signatureName>
        <signatureDate>2004-12-02</signatureDate>
    </ownerSignature>
</ownershipDocument>

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