St Donat's Castle, St Donats, Wales, is a medieval castle in the Vale of Glamorgan, about 16 miles (26 km) to the west of Cardiff, and about 1+1⁄2 miles (2.4 km) to the west of Llantwit Major. Positioned on cliffs overlooking the Bristol Channel, the site has been occupied since the Iron Age, and was by tradition the home of the Celtic chieftain Caradog. The present castle's origins date from the 12th century when the de Haweys and later Peter de Stradling began its development. The Stradlings held the castle for four hundred years, until the death of Sir Thomas Stradling in a duel in 1738.

John Whitlock Nicholl Carne (1817–1887) FSA, JP, DCL, was a Welsh landowner, magistrate, and barrister. His seat was Dimlands.