Naval trawlers were purpose-built or requisitioned and operated by the Royal Navy (RN), mainly during World Wars I and II. Vessels built to Admiralty specifications for RN use were known as Admiralty trawlers. All trawlers operated by the RN, regardless of origin, were typically given the prefix HMT, for "His Majesty's Trawler".
The trawler , built in 1906 at Hull and requisitioned September 1914 is the oldest surviving steam trawler in the world. She is beached at Grytviken in South Georgia, though there are plans to return her to Hull.
There were also 215 trawlers of no specific class These were commercial trawlers that the Admiralty requisitioned. The Royal Navy classified requisitioned trawlers by manufacturer, although such classes were more diverse than traditional naval classifications. Seventy-two requisitioned trawlers were lost.