The Implacable-class aircraft carrier consisted of two aircraft carriers built for the Royal Navy during World War II. Derived from the design of the Illustrious class, they were faster and carried more aircraft than the older ships. They were initially assigned to the Home Fleet when completed in 1944 and attacked targets in Norway as well as the German battleship Tirpitz. Subsequently, they were assigned to the British Pacific Fleet (BPF).

The Illustrious class was a class of aircraft carrier of the Royal Navy that included some of the most important British warships in the Second World War. They were laid down in the late 1930s as part of the rearmament of British forces in response to the emerging threats of Nazi Germany, Fascist Italy and Imperial Japan.