CCGS W.E. Ricker was a Canadian Coast Guard offshore fisheries research vessel. The ship was originally constructed as the commercial fishing trawler Callistratus, but was purchased by the Government of Canada in 1984 and converted to a fisheries research vessel and renamed W.E. Ricker. The vessel entered service with the Department of Fisheries and Oceans in 1986 and was transferred to the Canadian Coast Guard in 1995 after the two fleets were amalgamated. The ship was assigned to the West Coast of Canada and was decommissioned on 14 March 2017.