HMS Polyanthus was a Flower-class corvette of the Royal Navy. She was launched on 30 November 1940 from Leith Docks on the Firth of Forth, at an estimated cost of £55,000. Polyanthus was sunk by the German submarine U-952 using new German weapons technology on 20 September 1943 about 1,000 miles southwest of Reykjavík during convoy escort duty in the Battle of the North Atlantic.