HMS Churchill was the first of three Churchill-class[a] nuclear fleet submarines that served with the Royal Navy.

[1] Churchill, the Royal Navy's fourth nuclear-powered fleet submarine was ordered on 21 October 1965, and was laid down at Vickers Shipbuilding and Engineering Limited (VSEL)'s Barrow-in-Furness shipyard on 30 June 1967.

[3] Following a collision between sister submarine Warspite and a Soviet Echo II-class submarine in the Barents Sea on 9 October 1968, the fin of Churchill, still under construction at Barrow, was used to replace Warspite's fin, which had been badly damaged in the collision.

[3] Churchill was chosen to trial the first full-size submarine pump jet propulsion.

[8] Later British submarine classes also featured the pump jet, although first-of-class vessels Swiftsure and Trafalgar were fitted with propellers at build.