No. 439 Squadron RCAF was a unit of the Royal Canadian Air Force, formed during World War II. No. 123 (Army Co-operation) Squadron was formed on 15 January 1942 and flew army training operations in Ontario and Nova Scotia. It was renumbered No. 439 (Fighter Bomber) Squadron on December 31, 1943 when it transferred to Wellingore, England and spent the war in England, France, Belgium, The Netherlands and Germany.