Powderham Castle is a fortified manor house situated within the parish and former manor of Powderham, within the former hundred of Exminster, Devon, about 6 miles (9.7 km) south of the city of Exeter and 1⁄4 mile (0.4 km) north-east of the village of Kenton, where the main public entrance gates are located. It is a Grade I listed building. The park and gardens are Grade II* listed in the National Register of Historic Parks and Gardens.

It is situated on flat, formerly marshy ground on the west bank of the River Exe estuary where it is joined by its tributary the River Kenn. On the opposite side of the Exe is the small village of Lympstone. Starting with a structure built sometime after 1390, the present castle was expanded and altered extensively in the 18th and 19th centuries. The castle remains the seat of the Courtenay family, Earls of Devon.