<SUBMISSION>
<ACCESSION-NUMBER>0001127602-08-000507
<TYPE>4
<PUBLIC-DOCUMENT-COUNT>1
<PERIOD>20080125
<FILING-DATE>20080129
<DATE-OF-FILING-DATE-CHANGE>20080129
<ISSUER>
<COMPANY-DATA>
<CONFORMED-NAME>OCEANFIRST FINANCIAL CORP
<CIK>0001004702
<ASSIGNED-SIC>6035
<IRS-NUMBER>223412577
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<BUSINESS-ADDRESS>
<STREET1>975 HOOPER AVE
<CITY>TOMS RIVER
<STATE>NJ
<ZIP>08753-8396
<PHONE>7322404500
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>975 HOOPER AVENUE
<CITY>TOMS RIVER
<STATE>NJ
<ZIP>08723
</MAIL-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>OCEAN FINANCIAL CORP
<DATE-CHANGED>19951208
</FORMER-COMPANY>
</ISSUER>
<REPORTING-OWNER>
<OWNER-DATA>
<CONFORMED-NAME>OCEANFIRST FOUNDATION
<CIK>0001032213
<STATE-OF-INCORPORATION>DE
<FISCAL-YEAR-END>1231
</OWNER-DATA>
<FILING-VALUES>
<FORM-TYPE>4
<ACT>34
<FILE-NUMBER>001-11713
<FILM-NUMBER>08557552
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>975 HOOPER AVENUE
<CITY>TOMS RIVER
<STATE>NJ
<ZIP>08753
<PHONE>9082404500
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>975 HOOPER AVENUE
<CITY>TOMS RIVER
<STATE>NJ
<ZIP>08753
</MAIL-ADDRESS>
</REPORTING-OWNER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>form4.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-01-25</periodOfReport>

    <issuer>
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        <issuerName>OCEANFIRST FINANCIAL CORP</issuerName>
        <issuerTradingSymbol>OCFC</issuerTradingSymbol>
    </issuer>

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            <rptOwnerName>OCEANFIRST FOUNDATION</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>975 HOOPER AVENUE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>TOMS RIVER</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>08754</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isTenPercentOwner>1</isTenPercentOwner>
        </reportingOwnerRelationship>
    </reportingOwner>

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                <value>Common Stock</value>
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            <transactionCoding>
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            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
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                    <value>900</value>
                </transactionShares>
                <transactionPricePerShare>
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                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
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            <postTransactionAmounts>
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            <ownershipNature>
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                <transactionPricePerShare>
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                <transactionAcquiredDisposedCode>
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                <transactionPricePerShare>
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                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
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                <transactionShares>
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                <transactionAcquiredDisposedCode>
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            <transactionDate>
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                <transactionFormType>4</transactionFormType>
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                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>600</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>15.63</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
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            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1457413</value>
                </sharesOwnedFollowingTransaction>
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            <ownershipNature>
                <directOrIndirectOwnership>
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                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
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            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>400</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>15.64</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
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                <sharesOwnedFollowingTransaction>
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                </sharesOwnedFollowingTransaction>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
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        <nonDerivativeTransaction>
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                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionAmounts>
                <transactionShares>
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                <transactionShares>
                    <value>900</value>
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                <transactionPricePerShare>
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                <transactionAcquiredDisposedCode>
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                <sharesOwnedFollowingTransaction>
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                </sharesOwnedFollowingTransaction>
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            <ownershipNature>
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                <transactionShares>
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                <transactionPricePerShare>
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                <transactionAcquiredDisposedCode>
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            <ownershipNature>
                <directOrIndirectOwnership>
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                <value>Common Stock</value>
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                <transactionPricePerShare>
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            <ownershipNature>
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        <nonDerivativeTransaction>
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            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>500</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>15.69</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
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            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
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            <ownershipNature>
                <directOrIndirectOwnership>
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                <transactionPricePerShare>
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            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
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        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
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                <value>Common Stock</value>
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                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
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                <transactionShares>
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                <transactionPricePerShare>
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        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
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            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>600</value>
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                <transactionPricePerShare>
                    <value>15.72</value>
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                <transactionAcquiredDisposedCode>
                    <value>D</value>
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            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1450093</value>
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        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
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                <transactionFormType>4</transactionFormType>
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            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>300</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>15.73</value>
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            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1449793</value>
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            <ownershipNature>
                <directOrIndirectOwnership>
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        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
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            <transactionDate>
                <value>2008-01-25</value>
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            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
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            <transactionTimeliness></transactionTimeliness>
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                <transactionShares>
                    <value>200</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>15.74</value>
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            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
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            <ownershipNature>
                <directOrIndirectOwnership>
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        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes></footnotes>

    <ownerSignature>
        <signatureName>/s/ John K. Kelly, Power of Attorney</signatureName>
        <signatureDate>2008-01-29</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
