HMS Lagan was laid down on 7 January 1942, at Smiths Dock Co., South Bank-on-Tees and launched 28 July 1942, commissioning on 21 December 1942. She was built to the RN's specifications as a Group 2 River-class frigate. Serving in the North Atlantic during World War 2, on convoy escort duties. On 12 May 1943, she, the destroyer HMS Broadway and Swordfish aircraft from HMS Biter sank the German submarine U-89. The next day, Lagan and the Canadian corvette HMCS Drumheller sank U-753. Whilst Lagan was part of Convoy ON-202, she was attacked by U-270, at 04:57 on 20 September 1943. A GNAT (German Navy Acoustic Torpedo) torpedo struck the stern of Lagan, inflicting serious damage to the ship and killing 29. She was taken in tow to the Mersey, where she was declared unrepairable. Her wreck was sold for scrap in Troon on 21 May 1946.