Foulksrath Castle, Anglo-Norman tower house in Jenkinstown, Ireland

Foulksrath Castle is a four-storey stone tower in Jenkinstown, Ireland, with a crenellated roofline and a central spiral staircase connecting all floors. It still sits within its original moat and is flanked by old outbuildings and perimeter walls.

A fortified, moated dwelling was first built on the site in 1349 for the De Frene family; the present tower house was erected in the early 15th century by their relatives, the Purcells. The Purcells sided with the Royalists in the English Civil War, and Cromwell confiscated the estate, dividing it among three officers. The castle later passed through the Dawson, Wright and Swift families before An Óige bought it in 1946 and converted it into a youth hostel, which closed in 2009.

The castle's name is thought to come from Fulco De Frene, who died in 1349 and fought at Crécy and the Siege of Calais. Local lore holds that a woman's ghost walks the tower with the scent of wild flowers or lilacs, and a BBC ghost-hunting crew filmed there in 1992.

Foulksrath Castle is privately owned and not open to visitors, so the tower, bawn wall and moat can only be seen from outside. It stands about 12 km from Kilkenny, reached by road through Jenkinstown.

In 1857 Godwin Meade Pratt Swift patented Ireland's first aircraft, an "aerial chariot", and launched it by catapult from the tower's top with his butler as pilot; it nosedived at once and the butler survived with multiple broken bones. The castle is privately owned and cannot be visited.