The 4728th Air Defense Group is a discontinued United States Air Force organization. Its last assignment was with the New York Air Defense Sector at Dover Air Force Base. The group was formed to provide a single command and support organization for the two fighter interceptor squadrons of Air Defense Command (ADC), that were tenants at Dover, a Military Air Transport Service (MATS) base. It was also assigned a maintenance squadron to perform aircraft maintenance. It was discontinued after the 46th Fighter-Interceptor Squadron inactivated in 1958, leaving only a single fighter squadron at Griffiss.