Frontenac was commissioned at Kingston on October 26, 1943, arrived at Halifax in mid-December and carried out working-up exercises in St. Margaret's Bay in January, 1944. She was then assigned to EG 9, Londonderry, and made the crossing in March as escort to convoy SC.154. It was decided, however, the EG 9 should be made up only of frigates, and Frontenac returned to St. John's where in May she joined EG C-1. She left Belfast December 19 to escort ON.273, her last westbound convoy, and early in January, 1945, commenced three months' refit at Liverpool, N.S. On Completion she was assigned to Halifax Force and sent to Bermuda to work up, but saw little further service before being paid off at Halifax on July 22. She was then taken to Sorel, but was s old in October to the United Ship Corp. of New York.