Iruma Air Base (入間基地, Iruma-kichi) (ICAO: RJTJ) 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. Johnson AB was completely returned to the Government of Japan in 1978.

Currently, Iruma Air Base is home to the Air Defense Command Headquarters Flight Group. Aircraft located at the base include the U-4, NAMC YS-11, T-4, and Kawasaki C-1. Its annual air show on the November 3rd Culture Day holiday is a popular public event.