<SUBMISSION>
<ACCESSION-NUMBER>0000945094-04-000719
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20041201
<FILING-DATE>20041202
<DATE-OF-FILING-DATE-CHANGE>20041202
<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>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>ANDRESS JAMES G
<CIK>0001014093
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-11840
<FILM-NUMBER>041180425
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>C/O NEORX CORPORATION
<STREET2>410 W HARRISON
<CITY>SEATTLE
<STATE>WA
<ZIP>98119
<PHONE>2062817001
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>C/O XOMA LTD.
<STREET2>2910 SEVENTH STREET
<CITY>BERKELEY
<STATE>CA
<ZIP>94710
</MAIL-ADDRESS>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>c0001014093d20041202f4f.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>0001014093</rptOwnerCik>
            <rptOwnerName>ANDRESS JAMES G</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1381 NORTH ELM TREE ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>LAKE FOREST</rptOwnerCity>
            <rptOwnerState>IL</rptOwnerState>
            <rptOwnerZipCode>60045</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>JAMES G ANDRESS</signatureName>
        <signatureDate>2004-12-02</signatureDate>
    </ownerSignature>
</ownershipDocument>

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