4. Flieger Division (4th Air Division) was one of the primary divisions of the German Luftwaffe in World War II. It was formed on 1 August 1938 in Munich from the Höheren Fliegerkommandeur 5. The Division was redesignated 21. Flieger-Division on 1 November 1938 and relocated to Braunschweig and again renamed to 4. Flieger Division on 1 February 1939. The unit was relocated to Düsseldorf on 1 October 1939 and redesignated IV. Fliegerkorps on 11 October 1939 and reformed again in June 1943 in Smolensk.