Commissioned on December 4, 1941, at Quebec City, she arrived at Halifax on December 13 and after working up did escort duty between Halifax and St. John's. In July, 1942, she was transferred to Halifax Force as escort to Quebec City-Hamilton Inlet (Labrador) convoys. Lunenburg arrived at Sydney on August 31 to join Gulf Escort Force, but two weeks later was detached for Operation "Torch" duties. Arriving at Londonderry on September 27, she proceeded to Liverpool for extra A/A armament and in November began a four-month stint escorting convoys between the U.K. and the Mediterranean. At the end of March, 1943, she returned to Liverpool for a major refit, including fo'c's'le extension, completing on August 17. After a brief sojourn in Canadian waters she was assigned to EG 6, Western Approaches Command, arriving at Plymouth late in November to join. For the next five months she operated in support of convoys between the U.K. and Gibraltar, and between Londonderry and other U.K. ports, as well as patrolling the Northwestern Approaches from her Londonderry base. When the group's corvettes were replaced with frigates in April, 1944, Lunenburg went to Western Approaches Command Greenock, to be based at Portsmouth for invasion duties. For the next five months she was employed primarily in the English Channel. She left Londonderry on September 23 for refit begun at Saint John, N.B., but completed at Halifax in mid-January, 1945. Following work-ups in Bermuda she returned to the U.K. via the Azores, to serve with Plymouth Command until the end of the war. In May, 1945, she visited St. Helier during the reoccupation of the Channel Islands. She left Greenock in mid-June for Halifax, was paid off at Sorel on July 23, and broken up at Hamilton in 1946.
Focsle Extended, Liverpool, UK, 17 Aug 43