Lissoughter or Lissoughter Hill (Irish: Cnoc Lios Uachtair, meaning 'hill of the upper ring-fort') is a prominent hill between the Twelve Bens and Maumturks mountain ranges, at the southern entrance to the Inagh Valley, in the Connemara National Park of County Galway, Ireland. With a height of 401 metres (1,316 ft), it does not qualify to be an Arderin or a Vandeleur-Lynam, however, its prominence of 336 metres (1,102 ft) ranks it as a Marilyn.

A quarry on Lissoughter's southern slopes (the Lissoughter-Derryclare quarry, named after the peak and the neighbouring Derryclare mountain), is a noted source of the green-coloured Connemara marble (sometimes called Connemara Lissoughter Marble). As an isolated standalone peak, it is less frequented by hill-walkers, however, it is regarded for its views of the two ranges and the southern boglands of Connemara.

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  Lough Inagh and Lissoughter (back, right), viewed from Knockpasheemore
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  Lissoughter, viewed from forest in Recess, County Galway
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  Connemara marble from the Lissoughter quarry.

• MountainViews Online Database (Simon Stewart) (2013). A Guide to Ireland's Mountain Summits: The Vandeleur-Lynams & the Arderins. Collins Books. ISBN 978-1-84889-164-7.
• Tim Robinson (2007). Connemara: Listening to the Wind. Penguin. ISBN 978-1844880669.
• Dillion, Paddy (2001). Connemara: Collins Rambler's guide. Harper Collins. ISBN 978-0002201216.
• Dillion, Paddy (1993). The Mountains of Ireland: A Guide to Walking the Summits. Cicerone. ISBN 978-1852841102.

• Twelve Bens, major range in Connemara
• Maumturks, major range in Connemara
• List of Marilyns in the British Isles

• MountainViews: The Irish Mountain Website, Lissoughter
• MountainViews: Irish Online Mountain Database
• The Database of British and Irish Hills , the largest database of British Isles mountains ("DoBIH")
• Hill Bagging UK & Ireland, the searchable interface for the DoBIH