Nagshead SSSI is a 297 acres (120 ha) biological Site of Special Scientific Interest located within RSPB Nagshead, near Parkend, in the Forest of Dean, Gloucestershire. It was notified in 1972 and is listed in the 'Forest of Dean Local Plan Review' as a Key Wildlife Site. The SSSI consists of two units of assessment by Natural England and occupies a relatively small area on the eastern side of the much larger 1,250 acres (510 ha) nature reserve, all of which is jointly managed by the RSPB and Forestry England.