Commissioned at Victoria on November 15, 1943, Port Colborne arrived at Halifax January 9, 1944, and proceeded to Bermuda to work up in February. Late in April she sailed for Londonderry to join EG 9, which was based there. She remained on patrol and escort duty in U.K. waters, including participation on D-Day, except for a round trip to North Russia in December 1944, with convoys JW.62 and RA.62. She left Londonderry for Halifax February 21, 1945, and on September 24 completed tropicalization refit at Liverpool, N.S. On November 7 she was paid off at Halifax and laid up in reserve in Bedford Basin, and in 1947 was broken up at Sydney.