<SUBMISSION>
<ACCESSION-NUMBER>0001179110-04-011557
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20040521
<FILING-DATE>20040526
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>BYRNE JOHN JOSEPH
<CIK>0001181359
<ASSIGNED-SIC>6331
<STATE-OF-INCORPORATION>D0
<FISCAL-YEAR-END>1231
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>000-49799
<FILM-NUMBER>04832574
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>C/O WHITE MOUNTAINS INSURANCE GROUP, LTD
<STREET2>80 SOUTH MAIN STREET
<CITY>HANOVER
<STATE>NH
<ZIP>03755
<PHONE>6036402200
</BUSINESS-ADDRESS>
</REPORTING-OWNER>
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>OVERSTOCK COM INC
<CIK>0001130713
<ASSIGNED-SIC>7389
<IRS-NUMBER>870634302
<STATE-OF-INCORPORATION>UT
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>6322 SOUTH 3000 EAST
<STREET2>STE 100
<CITY>SALT LAKE CITY
<STATE>UT
<ZIP>84121
<PHONE>8019473100
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>6322 SOUTH 3000 EAST
<STREET2>STE 100
<CITY>SALT LAKE CITY
<STATE>UT
<ZIP>84121
</MAIL-ADDRESS>
</ISSUER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 4 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-05-21</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001130713</issuerCik>
        <issuerName>OVERSTOCK COM INC</issuerName>
        <issuerTradingSymbol>OSTK</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001181359</rptOwnerCik>
            <rptOwnerName>BYRNE JOHN JOSEPH</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>6322 SOUTH 3000 EAST</rptOwnerStreet1>
            <rptOwnerStreet2>SUITE 100</rptOwnerStreet2>
            <rptOwnerCity>SALT LAKE CITY</rptOwnerCity>
            <rptOwnerState>X1</rptOwnerState>
            <rptOwnerZipCode>84121</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable></nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Incentive stock option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>31.13</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2004-05-21</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>5000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>31.13</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <value>2005-05-21</value>
                <footnoteId id="F1"/>
            </exerciseDate>
            <expirationDate>
                <value>2009-05-20</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>5000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5000</value>
                    <footnoteId id="F2"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">The options vest as to 28% of the total option grant on the first anniversary of the grant date (i.e. 5/21/2005) and 2% of the total option grant every month thereafter.</footnote>
        <footnote id="F2">Reflects total amount of options outstanding held by the reporting person following this reported transaction.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ John J. Byrne</signatureName>
        <signatureDate>2004-05-25</signatureDate>
    </ownerSignature>
</ownershipDocument>

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