HMS Thermopylae (P355)

HMS Thermopylae (P355) was a T-class submarine of Britain's Royal Navy laid down on 26 October 1943 at Chatham Dockyard, and launched on 27 June 1945.

Completed early 1946 and was commissioned during March of that year. She immediately joined the 3rd Flotilla based in the Holy Loch.

She remained in service until December 1968 when she was put on the sale list. She was broken up at Troon during 1971.