HMS Penylan was a destroyer of the Royal Navy. She was a member of the third subgroup of the class, and saw service in the Second World War, before being sunk by German E-boats in 1942.
Penylan was ordered on 23 August 1940 under the 1940 War Emergency Programme from Vickers-Armstrongs, Barrow-in-Furness. She was laid down as Job No J3585 on 4 June 1941 and launched on 17 March 1942. She was commissioned into service on 25 August 1942, and after working up, was assigned to the 1st Destroyer Flotilla. She was adopted by the civil community of the Borough and Rural District of Carmarthen as part of Warship Week during 1942.
Penylan sailed to Scapa Flow in September and spent the rest of the month working up with ships of the Home Fleet, after which she sailed to Portsmouth. She had to put into a commercial shipyard in London on 22 October after a number of defects came to light. She was under repair until 9 November when she sailed to Portsmouth and joined the 1st Destroyer Flotilla on patrol in the English Channel. She was deployed on 1 December to escort convoy PW-257. The convoy was attacked by E-boats on 3 December, and Penylan was torpedoed and sunk five miles south of Start Point by the E-boat S115. Five officers and 112 ratings were rescued. She was the shortest lived of the Hunts, spending only 30 days on active service. The wreck is designated as a protected place under the Protection of Military Remains Act 1986.