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

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2019-02-08</periodOfReport>

    <issuer>
        <issuerCik>0001674862</issuerCik>
        <issuerName>ASHLAND GLOBAL HOLDINGS INC</issuerName>
        <issuerTradingSymbol>ASH</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001258631</rptOwnerCik>
            <rptOwnerName>TEAL JANICE</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>7575 PELICAN BAY BLVD.</rptOwnerStreet1>
            <rptOwnerStreet2>APT. 801</rptOwnerStreet2>
            <rptOwnerCity>NAPLES</rptOwnerCity>
            <rptOwnerState>FL</rptOwnerState>
            <rptOwnerZipCode>34108</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
        </reportingOwnerRelationship>
    </reportingOwner>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Units</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2019-02-08</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1413</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>77.85</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>1413</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>14496</value>
                    <footnoteId id="F3"/>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each Restricted Stock Unit represents a right to receive one (1) share of Ashland Common Stock.</footnote>
        <footnote id="F2">Grant of deferred Restricted Stock Units pursuant to Ashland's Deferred Compensation Plan for Non-Employee Directors, and exempt under Rule 16b-3.  The Restricted Stock Units will vest one year after date of grant.  (One (1) Restricted Stock Unit in the Deferred Compensation Plan for Non-Employee Directors is the equivalent of one (1) share of Ashland Common Stock.)</footnote>
        <footnote id="F3">Balance includes 40 additional Restricted Stock Units acquired in lieu of cash dividends paid on March 15, 2018, 41 additional Restricted Stock Units acquired in lieu of cash dividends paid on June 15, 2018, 38 additional Restricted Stock Units acquired in lieu of cash dividends paid on September 15, 2018 and 46 additional Restricted Stock Units acquired in lieu of cash dividends paid on December 15, 2018, pursuant to Ashland's Deferred Compensation Plan and exempt under Rule 16b-3. One (1) Restricted Stock Unit is the equivalent of one (1) share of Ashland Common Stock.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Jennifer I. Henkel, Attorney-in-Fact</signatureName>
        <signatureDate>2019-02-12</signatureDate>
    </ownerSignature>
</ownershipDocument>
