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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2013-06-07</periodOfReport>

    <notSubjectToSection16>1</notSubjectToSection16>

    <issuer>
        <issuerCik>0001270400</issuerCik>
        <issuerName>VIRGIN MEDIA INC.</issuerName>
        <issuerTradingSymbol>VMED</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001240253</rptOwnerCik>
            <rptOwnerName>MOONEY JAMES</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O VIRGIN MEDIA INC.</rptOwnerStreet1>
            <rptOwnerStreet2>65 BLEECKER STREET, 6TH FLOOR</rptOwnerStreet2>
            <rptOwnerCity>NEW YORK</rptOwnerCity>
            <rptOwnerState>NY</rptOwnerState>
            <rptOwnerZipCode>10012</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

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        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
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            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionAmounts>
                <transactionShares>
                    <value>143674</value>
                </transactionShares>
                <transactionPricePerShare>
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                </transactionPricePerShare>
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                    <value>D</value>
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                <sharesOwnedFollowingTransaction>
                    <value>0</value>
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                    <value>D</value>
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    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>26.79</value>
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            <transactionDate>
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            <expirationDate>
                <value>2021-01-03</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>27226</value>
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            </underlyingSecurity>
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            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
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            <deemedExecutionDate></deemedExecutionDate>
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                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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            <transactionAmounts>
                <transactionShares>
                    <value>40000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
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                    <value>D</value>
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                <value>2021-10-03</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>40000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
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                    <value>0</value>
                </sharesOwnedFollowingTransaction>
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                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
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        </derivativeTransaction>
        <derivativeTransaction>
            <securityTitle>
                <value>Stock Option (Right to Buy)</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>23.24</value>
            </conversionOrExercisePrice>
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                <value>2013-06-07</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
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                <transactionFormType>4</transactionFormType>
                <transactionCode>D</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
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                <transactionShares>
                    <value>40000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F3"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
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            <exerciseDate>
                <footnoteId id="F3"/>
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            <expirationDate>
                <value>2022-06-11</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>40000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
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                <sharesOwnedFollowingTransaction>
                    <value>0</value>
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        </derivativeTransaction>
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    <footnotes>
        <footnote id="F1">Disposed of in exchange for shares of a new parent company, Liberty Global plc (&quot;LG plc&quot;), upon consummation of the combination of Virgin Media Inc. (&quot;Virgin Media&quot;) and Liberty Global, Inc. under LG plc (the &quot;Merger&quot;) pursuant to that certain agreement and plan of merger dated as of February 5, 2013, as amended, at an exchange rate of one share of common stock of Virgin Media Inc. for 0.2582 of a Class A LG plc ordinary share and 0.1928 of a Class C LG plc ordinary share and $17.50 in cash. The exercise price of such converted shares was adjusted accordingly.</footnote>
        <footnote id="F2">The option had become fully exercisable prior to the Merger and was exchanged upon the Merger for two options, the first exercisable for 0.4123 of a Class A LG plc ordinary share and the second exercisable for 0.3077 of a Class C LG plc ordinary share, in each case multiplied by the number of Virgin Media shares of common stock for which the Virgin Media option was exercisable.  The exercise price of such converted options was adjusted accordingly.</footnote>
        <footnote id="F3">The option vested and became fully exercisable upon the Merger and was exchanged for two options, the first exercisable for 0.4123 of a Class A LG plc ordinary share and the second exercisable for 0.3077 of a Class C LG plc ordinary share, in each case multiplied by the number of Virgin Media shares of common stock for which the Virgin Media option was exercisable.  The exercise price of such converted options was adjusted accordingly.</footnote>
    </footnotes>

    <remarks>The disposition of the referenced securities of Virgin Media, Inc. by the Reporting Person was made as a result of the business combination of Virgin Media Inc. and Liberty Global, Inc. with wholly-owned subsidiaries of LG plc, which mergers were consummated on June 7, 2013, prior to the filing date for the Current Report on Form 8-K to be filed by Virgin Media Inc. reporting such mergers.  The disposition of all such securities by the Reporting Person was approved and exempted pursuant to the Rule 16b-3 under the Securities Exchange Act.</remarks>

    <ownerSignature>
        <signatureName>/s/ James F. Mooney</signatureName>
        <signatureDate>2013-06-11</signatureDate>
    </ownerSignature>
</ownershipDocument>
