Lislaughtin Abbey, Franciscan friary in County Kerry, Ireland.

Lislaughtin Abbey is a ruined Franciscan friary 1.3 km north of Ballylongford, County Kerry, on the east bank of Ballylongford Creek south of the Shannon Estuary. Its church is a long house divided into choir and nave, with triple sedilia and thirty pointed windows of cut limestone. The square tower over the choir arch has collapsed. A two-storey building held the refectory and dormitory, and a garderobe stands to the northeast.

John O'Connor, Lord of Kerry Luachra and Iraghticonnor, founded the friary for the Observant Franciscans in 1470; Pope Sixtus IV granted permission in 1477. It was named after Saint Lachtin, who died in 622. English soldiers raided it twice during the 1580 siege of Carrigafoyle Castle, and it was dissolved, though friars returned in 1629.

The name Lios Laichtin means "Lachtin's dwelling," after Saint Lachtin, who brought Christianity to the area and died in 622. The church and graveyard stayed in use by local Catholics after the friary was dissolved, and some friars returned in 1629. Thomas fitz Gerald, heir of the Knight of Glin, was buried here in 1567 after his execution.

The ruins lie 1.3 km north of Ballylongford on the east bank of Ballylongford Creek, south of the Shannon Estuary, reached by local roads. The church and graveyard remain in use by the local Catholic population, so visitors should expect graves among the walls. The collapsed square tower once stood over the choir arch, and the thirty pointed windows are cut limestone.

During the siege of Carrigafoyle Castle in the 1580s, local people buried the precious silver Lislaughtin cross to protect it from English soldiers. The cross, commissioned in 1479, displays the artistic quality of medieval Irish craftsmanship and is now kept in the National Museum of Ireland.