The rearmament of Germany in the 1930s led to a change in primary role for Upper Heyford, as German targets were beyond the range of RAF bombers then in service.

Upper Heyford trained bomber crews on Handley Page Hampdens and Vickers Wellingtons, supported by Avro Ansons, switching to de Havilland Mosquitos in 1945.

[6][7] The following units have also been stationed at RAF Upper Heyford at some point (note that units moved out, from March to December 1942, while new runways were laid):[6] Squadrons;[6] In response to what was perceived as a growing worldwide threat, Strategic Air Command decided to house a strong force of American bomber aircraft in England.

On 26 June 1950, men of the 801st Engineer Aviation Battalion started work on extending the runway and constructing new hardstands for SAC's larger bombers such as Convair B-36 Peacemaker and Boeing B-50 Superfortress.

Over a period of years the 7509th ABS was redesignated a number of times, eventually becoming the 3918th Combat Support Group, until it was inactivated in 1965 when SAC turned control over Upper Heyford to the United States Air Forces in Europe.

One of the most notable events of 1954 was the arrival of the first of the truly massive Convair RB-36 Peacemakers, a small number of which flew in for a brief stay in June and July by the 5th Strategic Reconnaissance Wing.

Meanwhile, following nuclear tests behind the 'Iron Curtain' in the summer of 1962, a detachment of Lockheed U-2 reconnaissance aircraft operated from Upper Heyford in August to carry out air sampling and analysis at very high altitudes in order to determine the characteristics of latest Soviet weapons.

The 6985th Electronic Security Squadron also maintained a detachment at Upper Heyford, supporting Communications Intelligence Specialists flying on the RC-135s.

In 1964, it was decided that regular detachments of SAC bomber aircraft to England would cease altogether, with the last 'Reflex Alert' at Upper Heyford on 1 January 1965.

Shortly after arriving at Upper Heyford, the 20th TFW began converting to a new aircraft - the General Dynamics F-111E Aardvark (unofficially).

The 20th TFW participated in F-111 NATO and US unilateral operations Shabaz, Display Determination, Cold Fire, Ocean Safari, Datex, Priory, Reforger, Dawn Patrol, Highwood, Hammer, Open Gate (1982 at Ovar Air Base, Portugal) and others from January 1972 to October 1993.

Parental responsibility over the 42nd by the 20th TFW was short-lived, however, and on 1 June 1985, operational control of the squadron shifted to the 66th Electronic Combat Wing at Sembach Air Base, Germany.

[27] In March 1986, the 66th Electronic Combat Wing detached the 42nd ECS to the 20th TFW to take part in El Dorado Canyon, the raid on Libya.

Crews who flew those first few terrifying nights said that the illumination from the AAA was so bright that they didn't need the TFR to avoid the ground.

After the missile threat was suppressed, crews flew their attacks at altitudes around 20,000 feet (6,096 m), above the range of most Iraqi AAA systems.

During the war, the F-111Es attacked a range of targets, including power plants, petroleum refineries, airfields, nuclear-biological-chemical processing and storage facilities, and electronics sites throughout northern Iraq, When Desert Storm ended, the wing had deployed 458 personnel, flown 1,798 combat sorties without a loss, and dropped 4,714 tons of ordnance.

With the end of the Cold War, the 20th TFW was deemed no longer necessary in the United Kingdom, and the USAF presence at RAF Upper Heyford was gradually phased down.

The next aircraft, 68-061 The Last Roll of Me Dice, departed for the Aerospace Maintenance and Regeneration Center at Davis Monthan AFB Arizona, in the USA.

[28] The runways are now home to a variety of wildlife including the scarce lowland calcareous grassland and bird species such as peregrine falcon, Eurasian skylark and common buzzard.

Graffiti has also occurred, as well as the whole hospital suffering from damage from leaking rainwater that has subsequently caused extensive mould, damp floors and a flooded cellar.

In 2009 Dorchester Group acquired Heyford Park from previous owners The North Oxfordshire Consortium, with plans to redevelop the former airfield into more than 1000 new homes alongside a new employment hub.

In 2018 Dorchester Group submitted a new Masterplan application to Cherwell District Council to create 1600 additional homes as well as an employment hub for creative industries.

In 2019 the newly refurbished Heritage Centre was opened by Dorchester Group displaying a range of items from the site’s history and running guided tours of the airfield, including giving access into some of the historic buildings.