The 564th Air Defense Group  is a disbanded United States Air Force organization.  Its last assignment was with the 4707th Air Defense Wing, at Otis Air Force Base, Massachusetts, where it was inactivated in 1955.  The group was originally activated as the 564th Air Service Group, a support unit for a combat group at the end of World War II but never deployed before it was inactivated in 1945.
 The group was activated once again in 1952 as the 564th Air Base Group to replace the support elements of the inactivating 33d Fighter-Interceptor Wing.  A year later Air Defense Command (ADC) established it as an operational headquarters for fighter-interceptor squadrons as well.  It was replaced in 1955 when ADC transferred its mission, equipment, and personnel to the 33d Fighter Group in a project that replaced air defense groups commanding fighter squadrons with fighter groups with distinguished records during World War II.
 The group was activated during World War II at Stinson Field, Texas as the 564th Air Service Group in 1944 and trained to support a single combat group in an overseas theater. Its 995th Air Engineering Squadron would provide maintenance that was beyond the capability of the combat group, its 1002nd Air Materiel Squadron would handle all supply matters, and its Headquarters & Base Services Squadron would provide other support. The group was inactivated before it could be deployed overseas. It was disbanded in 1948.
 During the Cold War the group was reconstituted, redesignated as the 564th Air Base Group, and activated at Otis Air Force Base, Massachusetts in 1952 in a major reorganization of Air Defense Command (ADC) responding to ADC's difficulty under the existing wing base organizational structure in deploying fighter squadrons to best advantage. It replaced the 33rd Air Base Group as USAF host unit for Otis.  The group was assigned eight squadrons to perform its support responsibilities. It also assumed aircraft maintenance responsibility from the 33d Maintenance & Supply Group for units stationed at Otis. The operational elements of the inactivating 33d Fighter-Interceptor Wing were assigned to the 4707th Defense Wing.
 In 1953 the group was redesignated the 564th Air Defense Group and assumed responsibility for air defense of the Boston area.[citation needed]  It was assigned the 58th Fighter-Interceptor Squadron (FIS), flying Lockheed F-94 Starfire aircraft equipped with air intercept radar and armed with cannon, from the 4707th Defense Wing as its operational element. The 58th FIS was already stationed at Otis. In April 1953, the 437th Fighter-Interceptor Squadron, flying a newer model of the F-94 aircraft armed with Mighty Mouse rockets, was activated as a second operational squadron. The 58th FIS upgraded to the newer F-94s by June 1953 and both squadrons converted to Northrop F-89 Scorpion aircraft in June 1955. The group was inactivated and replaced by the 33d Fighter Group (Air Defense) on 18 August 1955 as result of ADC's Project Arrow, which was designed to bring back on the active list the fighter units which had compiled memorable records in the two world wars. The group was disbanded once again in 1984.
  
  This article incorporates public domain material from the Air Force Historical Research Agency.