Admiral of the Fleet Sir Caspar John GCB (22 March 1903 – 11 July 1984) was a senior Royal Navy officer who served as First Sea Lord from 1960 to 1963. He was a pioneer in the Fleet Air Arm and fought in the Second World War in a cruiser taking part in the Atlantic convoys, participating in the Norwegian campaign and transporting arms around the Cape of Good Hope to Egypt for use in the western desert campaign. His war service continued as Director-General of Naval Aircraft Production, as naval air attaché at the British embassy in Washington D.C. and then as Commanding Officer of two aircraft carriers. He went on to serve as First Sea Lord and Chief of the Naval Staff in the early 1960s. In that capacity he was primarily concerned with plans for the building of the new CVA-01 aircraft-carriers.