Clifford Pelly was born in Poona, India on 17 June 1917, the son of Lieutenant Colonel Hutcheson Raymond Pelly, Indian Army, and Kathleen Mary Pelly. He joined the Royal Navy as a Cadet on 1 September 1934. He was promoted to Midshipman on 1 May 1935 and appointed to the battleship HMS ORION on the same date. Promotion to Sub Lieutenant followed on 1 August 1938.

He was appointed to HMS DOLPHIN ‘for the Submarine Course‘ on 5 September 1938 and, on 16 October 1938, he was appointed to the Submarine Depot Ship HMS MEDWAY ‘for Submarines‘ and then to HMS PANDORA as Third Hand on 6 May 1939. He was next appointed to HMS L27 as First Lieutenant on 20 February 1940, followed by HMS STURGEON as First Lieutenant on 12 September 1941. Clifford Pelly served in HMS OTWAY as First Lieutenant from 13 March 1942 prior to commencing his Commanding Officer Qualifying Course on 20 July 1942.

Clifford Pelly was appointed to HMS P511 in command on 31 August 1942, then HMS SEA DOG in command on 17 March 1943. For his services in SEA DOG, Pelly was awarded the DSC (see London Gazette dated 29 February 1944) for successful attacks off the coast of Norway and operations supporting commando troops in Spitsbergen. He was appointed to HMS STRATAGEM in command on 24 March 1944.

STRATAGEM left Trincomalee on 10 November 1944 with orders to patrol in the vicinity of Malacca. On 18 November 1944, Clifford Pelly fired a salvo of three torpedoes at an escorted Japanese convoy and one hit was seen on the Nichinan Maru. After a counterattack by the escort, he fired a single torpedo from the stern tube at the target, which had not sunk, and this second attack resulted in the target sinking. On 22 November 1944, a Japanese aircraft spotted STRATAGEM and passed the details to a destroyer which made a depth charge attack.

STRATAGEM was severely damaged, began to flood and, although Lieutenant Pelly attempted to surface the submarine, he was unsuccessful, and it sank to the bottom. According to Lieutenant D C Douglas (the Senior Survivor) only ten of the fourteen men alive in the forward compartment after the attack reached the surface but, after escaping, only eight were picked up alive by the Japanese. Clifford Pelly was not among them. Of the eight taken Prisoner of War only three survived at the end of the War.

Clifford Pelly of Taunton, Somerset is commemorated on the Portsmouth Naval Memorial on Panel 81 Column 1.