Iruma Air Base is a Japan Air Self-Defense Force (JASDF) base located in the city of Sayama, Saitama Prefecture, north of western Tokyo, Japan. It was the airfield for the Imperial Japanese Army Air Force Academy until 1945, when it became Johnson Air Force base of the United States Air Force during and after the occupation of Japan. Currently, Iruma Air Base is home to the Air Defense Command Headquarters Flight Group.