Hill-Norton served during the Second World War initially as a gunnery instructor at HMS "Excellent" and then as gunnery officer on the cruiser HMS "Cairo" operating on the Western Approaches and in the North Sea and taking part in the Norwegian Campaign in Spring 1940. He then transferred to the cruiser which took part in the Arctic convoys. He joined the staff of the gunnery division at the Admiralty in 1943 and, having been promoted to lieutenant commander on 1 April 1944, became gunnery officer on the battleship operating in the Eastern Fleet later that year. With HMS "Howe" he took part in the attack on the Sakishima Islands.