A flak corps () was a massed anti-aircraft (AA) artillery formation employed by the Luftwaffe for anti-aircraft, antitank, and fire support operations in World War II. A Flakkorps was a flexible organization that was made up of a varying number of AA regiments, brigades, or divisions. It was roughly equivalent in strength to a brigade or a division. A total of six flak corps were organized by Germany during the war. The flak corps, while mainly intended to support ground units with concentrated anti-aircraft fire, in many cases provided also antitank support.