Audley's Castle is a historic castle ruin located near Strangford Lough in County Down, Northern Ireland. The castle was built in the 16th century by John Audley, who was a member of the English nobility and served as an army commander during the Tudor conquest of Ireland.

The castle was built on the site of an earlier Norman castle and was designed as a fortified tower house, with walls that are over 1.5 meters thick in places. The castle was originally four stories high, but only the ground floor and part of the second floor survive today.

Audley's Castle was abandoned in the 17th century and fell into ruin, but it remains an important historical site and tourist attraction in Northern Ireland. Visitors can explore the castle ruins and enjoy scenic views of Strangford Lough and the surrounding countryside. The castle is managed by the Northern Ireland Environment Agency and is open to the public year-round.