HMS Tantivy was a British submarine of the third group of the T class. She was built as P319 by Vickers Armstrong, Barrow, and John Brown & Company, Clydebank, and launched on 6 April 1943. So far she has been the only ship of the Royal Navy to bear the name Tantivy.
Tantivy served in the Far East for much of her wartime career, where she sank the a Siamese sailing vessel, the Japanese merchant cargo ship Shiretoko Maru, the Japanese Communications Vessel No. 137, the Japanese barge No. 136 and the Japanese motor sailing vessel Tachibana Maru No.47, a Japanese tug, two Japanese coasters, a Japanese sailing vessel, the small Japanese vessels Chokyu Maru No.2, Takasago Maru No.3, and Otori Maru, as well as twelve small vessels that are unidentified. She also laid numerous mines.
She survived the war and continued in service with the Navy, finally being sunk as an anti-submarine target in the Cromarty Firth in 1951.