In May 1944 she was transferred to the 11th Escort Group to support the Allied landings in Normandy. On D-Day itself – 6 June 1944 – she was deployed with the Canadian destroyers , , and stationed in the entrance to the English Channel to prevent U-boat attacks on the invasion convoys. Later she was deployed with her group in the Bay of Biscay for anti-submarine operations. On 8 August she was unsuccessfully attacked by a glide bomb, and on the 13th she and Ottawa rescued survivors from which had been sunk with depth charges by a Sunderland aircraft. These duties continued into October, when she returned to Canada to refit. Conducted at Shelburne, Nova Scotia, the refit lasted from November 1944 to 20 March 1945. St. Laurent returned to service in April 1945, and was attached to the Halifax Escort Force for convoy defence off the east coast. After the German surrender on 6 May, she was employed as a troop transport, until paid off on 10 October 1945. The ship was sold for scrap and broken up in 1947.
