HMCS St. Eloi was one of twelve Battle-class naval trawlers constructed for and used by the Royal Canadian Navy (RCN) during the First World War. Following the war the ship was transferred to the Canadian Department of Marine and Fisheries and converted into a lightvessel. Re-designated Lightship No. 20, the vessel returned to RCN service in 1940 to become the gate vessel Gate Vessel 12 during the Second World War. After the war, the trawler returned to government service and was discarded in 1962.