HMS Cawsand Bay (K644) was a Bay-class anti-aircraft frigate of the British Royal Navy, named for Cawsand Bay in Cornwall. The ship was originally ordered from the Blyth Shipbuilding Company of Blyth, Northumberland on 25 January 1943 as the Loch Rowan, and laid down on 24 April 1944. However the contract was then changed, and the ship was completed to a revised design as a Bay-class anti-aircraft frigate, launched on 26 February 1945, and completed on 13 November 1945.