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

    <schemaVersion>X0202</schemaVersion>

    <documentType>4/A</documentType>

    <periodOfReport>2004-06-14</periodOfReport>

    <dateOfOriginalSubmission>2004-06-15</dateOfOriginalSubmission>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000940181</issuerCik>
        <issuerName>SKILLSOFT PUBLIC LIMITED CO</issuerName>
        <issuerTradingSymbol>SKIL</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001240189</rptOwnerCik>
            <rptOwnerName>MORAN CHARLES E</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>SKILLSOFT</rptOwnerStreet1>
            <rptOwnerStreet2>107 NORTHEASTERN BLVD</rptOwnerStreet2>
            <rptOwnerCity>NASHUA</rptOwnerCity>
            <rptOwnerState>NH</rptOwnerState>
            <rptOwnerZipCode>03062</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President &amp; CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>American Depositary Shares</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2004-06-14</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2004-06-14</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4212</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>4.06</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>4212</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>American Depositary Shares</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2004-06-14</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2004-06-14</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F3"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4212</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>8</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>0</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>American Depositary Shares</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2004-06-14</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2004-06-14</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F4"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2609</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>7.9628</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>558852</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Trust</value>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>American Depositary Shares</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2004-06-14</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2004-06-14</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F6"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>976</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>8</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>189358</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Trust</value>
                    <footnoteId id="F7"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>American Depositary Shares</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2004-06-14</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2004-06-14</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F8"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>976</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>8</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>189358</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Trust</value>
                    <footnoteId id="F9"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>American Depositary Shares</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2004-06-14</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2004-06-14</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F10"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>976</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>8</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>189358</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Trust</value>
                    <footnoteId id="F11"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>American Depositary Shares</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <transactionDate>
                <value>2004-06-14</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2004-06-14</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>S</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F12"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>976</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>8</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>189358</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>Trust</value>
                    <footnoteId id="F13"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Option to Purchase Ordinary Shares</value>
                <footnoteId id="F14"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>4.06</value>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2004-06-14</value>
            </transactionDate>
            <deemedExecutionDate>
                <value>2004-06-14</value>
            </deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>M</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>4212</value>
                    <footnoteId id="F2"/>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F16"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F15"/>
            </exerciseDate>
            <expirationDate>
                <value>2012-08-16</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Ordinary Shares</value>
                    <footnoteId id="F14"/>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>4212</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>994438</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">American Depositary Shares (ADSs) evidenced by American Depositary Receipts, each of which represents one Ordinary Share, nominal value 0.11 (Euro) per Ordinary Share of SkillSoft Public Limited Company.</footnote>
        <footnote id="F2">These shares were omitted from the reporting person's original Form 4.</footnote>
        <footnote id="F3">Sale made pursuant to Mr. Moran's Rule 10b5-1 Sales Plan adopted in December 2003.</footnote>
        <footnote id="F4">Sale made pursuant to the Susan M. Moran Revocable Trust DTD 11-23-94 Rule 10b5-1 Sales Plan adopted in December 2003.</footnote>
        <footnote id="F5">These ADSs were gifted to the Susan M. Moran Revocable Trust DTD 11-23-94 on May 15, 2003. Susan Moran, Mr. Moran's spouse, is the trustee of this trust. Mr. Moran disclaims beneficial ownership of these securities, and the filing of this report is not an admission that Mr. Moran is the beneficial owner of these securities for the purposes of Section 16 or any other purpose.</footnote>
        <footnote id="F6">Sale made pursuant to the Moran Children's Trust DTD FBO Kelly Moran Rule 10b5-1 Sales Plan adopted in December 2003.</footnote>
        <footnote id="F7">These ADSs are held by the Moran Children's Trust DTD 3-4-98 FBO Kelly Moran. Susan Moran, Mr. Moran's spouse, is the trustee of this trust.  Mr. Moran disclaims beneficial ownership of these securities, and the filing of this report is not an admission that Mr. Moran is the beneficial owner of these securities for the purposes of Section 16 or any other purpose.</footnote>
        <footnote id="F8">Sale made pursuant to the Moran Children's Trust DTD FBO Michael Moran Rule 10b5-1 Sales Plan adopted in December 2003.</footnote>
        <footnote id="F9">These ADSs are held by the Moran Children's Trust DTD 3-4-98 FBO Michael Moran. Susan Moran, Mr. Moran's spouse, is the trustee of this trust. Mr. Moran disclaims beneficial ownership of these securities, and the filing of this report is not an admission that Mr. Moran is the beneficial owner of these securities for the purposes of Section 16 or any other purpose.</footnote>
        <footnote id="F10">Sale made pursuant to the Moran Children's Trust DTD FBO Katie Moran Rule 10b5-1 Sales Plan adopted in December 2003.</footnote>
        <footnote id="F11">These ADSs are held by Moran Children's Trust DTD 3-4-98 FBO Katie Moran. Susan Moran, Mr. Moran's spouse, is the trustee of this trust. Mr. Moran disclaims beneficial ownership of these securities, and the filing of this report is not an admission that Mr. Moran is the beneficial owner of these securities for the purposes of Section 16 or any other purpose.</footnote>
        <footnote id="F12">Sale made pursuant to the Moran Children's Trust DTD FBO Kristin Moran Rule 10b5-1 Sales Plan adopted in December 2003.</footnote>
        <footnote id="F13">These ADSs are held by the Moran Children's Trust DTD 3-4-98 FBO Kristin Moran. Susan Moran, Mr. Moran's spouse, is the trustee of this trust. Mr. Moran disclaims beneficial ownership of these securities, and the filing of this report is not an admission that Mr. Moran is the beneficial owner of these securities for the purposes of Section 16 or any other purpose.</footnote>
        <footnote id="F14">Each issued and outstanding Ordinary Share of the issuer, or option to purchase an ordinary share of the issuer, is represented by one (1) ADS.</footnote>
        <footnote id="F15">414,295 of the shares subject to this option vested on August 16, 2003. 138,098 of the shares subject to this option vested on December 16, 2003. The remaining shares subject to the option vest each month thereafter.</footnote>
        <footnote id="F16">Not applicable; the transaction being reported is an exercise of an option to purchase Ordinary Shares of the issuer.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Greg Porto (For Charles Moran)</signatureName>
        <signatureDate>2004-06-17</signatureDate>
    </ownerSignature>
</ownershipDocument>

