The Westland Whirlwind was a British twin-engined fighter developed by Westland Aircraft. A contemporary of the Supermarine Spitfire and Hawker Hurricane, it was the first single-seat, twin-engined, cannon-armed fighter of the Royal Air Force.

Westland Aircraft was a British aircraft manufacturer located in Yeovil, Somerset. Formed as a separate company by separation from Petters Limited just before the start of the Second World War, Westland had been building aircraft since 1915. During the war the company produced a number of generally unsuccessful designs, but their Lysander would serve as an important liaison aircraft with the Royal Air Force. After the war the company focused on helicopters, and was merged with several other British firms to create Westland Helicopters in 1961.