Development on the Westland Scout began in the late 1950s, however not at the Westland company, but at Saunders-Roe. Saunders-Roe developed their Saro P.531 light utility helicopter, which itself was based on the design of a previous piston-powered helicopter. The Saro P.531 already had several prototypes built and tested by the time the company was acquisitioned by Westland, who in turn, decided to continue development of the P.531.

As a result, in the early 1960s, the Westland Scout was created. The Scout conducted its maiden flight in August 1960 and was well-received with both the British Army and Royal Navy during testing. Following the favorable reception, the helicopter was subsequently ordered into production for the Army as the Scout AH Mk.1.

As work on the Scout steadily progressed, Westland continued developing a navalized version of the vehicle in parallel. The ‘Sea Scout’, as it was initially designated, only featured several minor design differences from the base model, such as a wheeled undercarriage and foldable blades and tail section, along with some other differences. After being reviewed by the Royal Navy, the ‘Wasp’ as it eventually became known, entered service with the Royal Navy in 1963, alongside the Army’s Scout.

Both versions of the helicopter took part in combat operations during their service, most notably in Borneo, the Falklands and Northern Ireland. In the end, around 280 machines of both types were built, including export models.