HMCS Constance was a commissioned minesweeper of the Royal Canadian Navy (RCN) during the First World War. Originally built as a fisheries cruiser for the Department of Marine and Fisheries, upon completion she was transferred to the Department of Customs, and was used by the Customs Preventive Service. Along with sister ships CGS Curlew, and CGS Petrel, Constance was fitted with mine sweeping gear in 1912. All three vessels were taken into naval service after the outbreak of war in 1914, and were used for patrol or examination duties. After the war, Constance was sold for commercial use. Remaining in service until the early 1930s, she was chartered by the Customs Preventive Service in 1928-29.