favorite coalition: Allies
The squadron was initially formed as the No.1 RCAF Squadron at Trenton, Ontario on 21 September 1937. The unit arrived in the UK in June 1940 and was redesignated No.401 on March 1941 at RAF Digby. In early 1943, the 401 became part of the No.126 Wing, No.83 Group of the newly forming 2nd Tactical Air Force and supported the invasion of France and later moved to the continent to provide fighter cover as the Allies entered Germany. The squadron disbanded at Faßberg on 3 June 1945.