HMCS Longueuil was a River-class frigate that served in the Royal Canadian Navy during the Second World War. She served primarily as a convoy escort in the Battle of the Atlantic. She was named for Longueuil, Quebec. Longueuil was ordered in October 1941 as part of the 1942-1943 River-class building program. She was laid down on 17 July 1943 by Canadian Vickers Ltd. at Montreal and launched on 30 October 1943. Longueuil was commissioned into the RCN at Quebec City on 18 May 1944 with the pennant K672.