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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2014-12-01</periodOfReport>

    <issuer>
        <issuerCik>0001468516</issuerCik>
        <issuerName>AOL Inc.</issuerName>
        <issuerTradingSymbol>AOL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001623689</rptOwnerCik>
            <rptOwnerName>Sweet Lara</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>22000 AOL WAY</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>DULLES</rptOwnerCity>
            <rptOwnerState>VA</rptOwnerState>
            <rptOwnerZipCode>20166</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isOfficer>1</isOfficer>
            <officerTitle>SVP, Controller and CAO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, Par Value $0.01</value>
            </securityTitle>
            <transactionDate>
                <value>2014-12-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>6597</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>13971</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents restricted stock units granted pursuant to the AOL Inc. Stock Incentive Plan, as amended and restated (the &quot;Plan&quot;). This award of restricted stock units will vest over three years such that one third of the restricted stock units will vest on December 1, 2015, and the remaining two thirds will vest in two equal installments on December 1, 2016 and December 1, 2017. This award of restricted stock units will be paid in stock to the Reporting Person within sixty days of vesting.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Marie Amerasinghe as authorized signatory for Lara Sweet</signatureName>
        <signatureDate>2014-12-02</signatureDate>
    </ownerSignature>
</ownershipDocument>
