GC 21 Group de Chassee III/3 is one of the four fighter brigades of the Allied Air Force, and one of the two of the Armee de l'Air. Historically this brigade fought in the Battle of France and consisted primarilly of D.520 until the fall of France, where the aces of the brigade fled to Gibralter and joined the Free French Airforce.

GC 21 Group de Chassee III/3 serves as the home of 'Les Cigognes' which is the primary French Flying squad on the Allied side. This brigade is historically more European based out of the two French fighter brigades.