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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2015-04-01</periodOfReport>

    <issuer>
        <issuerCik>0000021344</issuerCik>
        <issuerName>COCA COLA CO</issuerName>
        <issuerTradingSymbol>KO</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001581491</rptOwnerCik>
            <rptOwnerName>BOTIN ANA</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O THE COCA-COLA COMPANY</rptOwnerStreet1>
            <rptOwnerStreet2>ONE COCA-COLA PLAZA</rptOwnerStreet2>
            <rptOwnerCity>ATLANTA</rptOwnerCity>
            <rptOwnerState>GA</rptOwnerState>
            <rptOwnerZipCode>30313</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, $.25 Par Value</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>2500</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Spanish limited company</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Phantom Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>0</value>
                <footnoteId id="F2"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2015-04-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>6288.8309</value>
                    <footnoteId id="F3"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>40.52</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F4"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F4"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock, $.25 Par Value</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>6288.8309</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>14735.4842</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">These shares are held by a Spanish limited company in which the reporting person indirectly holds a majority of the economic interest and over which she has investment control.</footnote>
        <footnote id="F2">Each phantom share unit is economically equivalent to one share of Common Stock.</footnote>
        <footnote id="F3">Consists of 6,169.7927 phantom share units credited to the reporting person under The Coca-Cola Company Directors' Plan effective January 1, 2013 (the &quot;Directors' Plan&quot;) for 2015 compensation, which may include voluntary deferred compensation, and 119.0382 phantom share units accrued under the Directors' Plan as a result of crediting phantom dividends.</footnote>
        <footnote id="F4">The phantom share units credited under the Directors' Plan are settled in cash the later of (i) January 15 of the year following the year in which the reporting person leaves the Board, or (ii) six months following the date on which the reporting person leaves the Board.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Karen V. Danielson, attorney-in-fact for Ana Botin</signatureName>
        <signatureDate>2015-04-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
