The Westland WS-61 Sea King is a British licence-built version of the American Sikorsky S-61 helicopter of the same name, built by Westland Helicopters. The aircraft differs considerably from the American version, with Rolls-Royce Gnome engines (derived from the US General Electric T58), British-made anti-submarine warfare systems and a fully computerised flight control system. The Sea King was primarily designed for performing anti-submarine warfare (ASW) missions.

As of 2013, the WS-61 Sea King remains in operation in Britain, as well as multiple export customers: Germany, Norway, Egypt and India.