In Which We Serve is a 1942 British patriotic war film directed by Noël Coward and David Lean, who made his debut as a director. It was made during the Second World War with the assistance of the Ministry of Information.

HMS Kelly was a K-class destroyer of the British Royal Navy, and flotilla leader of her class. She served through the early years of the Second World War; in Home Waters, off Norway and in the Mediterranean. Throughout her service, Kelly was commanded by Lord Louis Mountbatten, as commander of the 5th Destroyer Flotilla. She was lost in action in 1941 during the Battle of Crete.