<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2012-08-13</periodOfReport>

    <dateOfOriginalSubmission>2012-08-13</dateOfOriginalSubmission>

    <issuer>
        <issuerCik>0001288776</issuerCik>
        <issuerName>Google Inc.</issuerName>
        <issuerTradingSymbol>GOOG</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001198046</rptOwnerCik>
            <rptOwnerName>HENNESSY JOHN L</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O GOOGLE INC.</rptOwnerStreet1>
            <rptOwnerStreet2>1600 AMPHITHEATRE PARKWAY</rptOwnerStreet2>
            <rptOwnerCity>MOUNTAIN VIEW</rptOwnerCity>
            <rptOwnerState>CA</rptOwnerState>
            <rptOwnerZipCode>94043</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Class A Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2012-08-13</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>25</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>650.00</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>1295</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Class A Common Stock</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4308</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Trust</value>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Google Stock Unit</value>
                <footnoteId id="F2"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>363</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Google Stock Unit</value>
                <footnoteId id="F3"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>495</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Google Stock Unit</value>
                <footnoteId id="F4"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>345</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Google Stock Unit</value>
                <footnoteId id="F5"/>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>590</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>Option To Purchase Class B Common Stock</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>20.00</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <footnoteId id="F6"/>
            </exerciseDate>
            <expirationDate>
                <value>2014-04-28</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Class B Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>74</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>74</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each share of Class A Common Stock was issued upon the conversion of one share of Class B Common Stock at the election of Reporting Person.</footnote>
        <footnote id="F2">the GSUs vest as follows: 1/4th of the GSUs vested on 6/2/2011 and 1/16th of the GSUs vests each quarter thereafter, subject to continued service on such vesting dates.</footnote>
        <footnote id="F3">The GSUs vest as follows: 1/48th of GSUs shall vest on the 25th day of the first month after the vesting start date and an additional 1/48th will vest monthly thereafter, subject to continued service on such vesting dates. Vesting start date is July 6, 2011.</footnote>
        <footnote id="F4">The GSUs vest as follows: 1/4th of the GSUs vested on August 5, 2010 and 1/16th of the GSUs vest each quarter thereafter, subject to continued service on such vesting dates.</footnote>
        <footnote id="F5">The GSUs vest as follows: 1/48th vests on the 25th calendar day of the month following the vesting start date and an additional 1/48th vests monthly on the 25th day of each month thereafter, subject to continued service on such vesting dates. Vesting start date is July 11, 2012.</footnote>
        <footnote id="F6">The option is fully vested.</footnote>
    </footnotes>

    <remarks>This Form 4/A is filed to correct the amount of shares sold and the sale price per share that were inadvertently misstated on the original Form 4.</remarks>

    <ownerSignature>
        <signatureName>/s/ Valentina Margulis, as attorney-in-fact for John L. Hennessy</signatureName>
        <signatureDate>2012-08-13</signatureDate>
    </ownerSignature>
</ownershipDocument>
