Another of the four operational expansion scheme airfields under No. 2 Group when war was declared, Watton was built on free-draining soil between the B1108 and B111 roads just to the east of the small town of Watton. Permanent buildings included four Type C hangars in a crescent fronting the bombing circle of the 250-acre grass aerodrome. The main contractor was John Laing & Son Ltd.
The usual practice followed of placing two squadrons on the station as soon as it was ready for occupation, this being in March 1939 when No. 21 Squadron brought its Blenheims from Eastchurch and No. 34 came with the same type from Upper Heyford. No. 34's association with Watton only lasted six months, the squadron being sent out to Singapore whereupon No. 82 Squadron moved in from Cranfield. From June to October 1940, No. 21 Squadron was loaned to Coastal Command operating out of Lossiemouth thus largely escaping the slaughter that befell most Blenheim bomber squadrons during that summer. No. 105 Squadron arrived in July 1940 to be re-equipped with Blenheims after its mauling with Battles during the German Blitzkrieg in France. No. 82 Squadron carried out most of the offensive tasks for Watton's Blenheims, flying more raids than any other Blenheim squadron in No. 2 Group. However, it also suffered by far the heaviest losses and between September 27, 1939 and March 1942 when it was posted to Malta, 62 Blenheims were missing m action with another 25 lost in operational accidents, many of these losses occurring flying from Bodney - Watton's satellite - or Lossiemouth. All told, 100 Blenheims were lost by Nos.21 and 82 Squadrons while flying from Watton.
No. 21 Squadron had been sent to Malta in December 1941 but was disbanded there and re-formed at Bodney the following March. During 1941 several concrete pan hardstandings were constructed on well-dispersed sites around the airfield totalling, it is believed, 24.
In January 1942, No. 17 (Pilots) Advanced Flying Unit was formed at Watton to provide refresher courses. Equipped mainly with Miles Masters, this organisation became the sole resident of Watton after No. 82 Squadron left. The reason for a training unit occupying a front line operational airfield is believed to be due to a shortage of airfields for flying training. It continued in residence until May 1943.
In August 1942 Watton had been allocated to the USAAF as a bomber base and two months later it was, in addition, scheduled for an air depot. By the spring of 1943 the overloaded airfield building programme resulted in a decision not to put down hard runways on any more of the existing grass surface airfields, Watton being re-allocated for use as a fighter station. The Americans arrived in August 1943 with air service groups maintaining the B-24 Liberators of the 2nd Bomb Division, Watton officially transferring to the USAAF on October 4, 1943.
Construction of the air depot, officially known as Neaton but actually built on the opposite side of the airfield at Griston, consisted of 24 loop hardstandings, three grouped T2 hangars and numerous Nissentype workshops. Early in 1944 a provisional reconnaissance unit was established becoming the 802nd (P) Reconnaissance Group in April and the 25th Bomb Group (R) in August. Two squadrons operated Mosquitos and the third B-24s before converting to B-17s.
During the winter of 1943-44 the grass runways were reinforced with steel mat but in July 1944 the 899th Engineer Battalion, US Army, laid a 2,000-yard concrete runway on the axis 11-29. A concrete perimeter track with 41 loops was also put down linking with 14 of the existing pan hardstandings.
Watton was returned to the RAF on August 15, 1945 when the station became the home of the Radio Warfare Establishment, later re-titled the Central Signals Establishment. The composition of this organisation varied over the next two decades. Following the departure of the CSE regular flying from Watton ceased but it continued as a major air traffic control centre with Eastern Radar until the 1980s. Then in the 1990s, the airfield came into use by the Army in connection with the nearby Stanford Training Area. Part of the camp put up for sale in 1995 was sold to a developer for the creation of a new housing estate. Three of the type C hangars have been used for grain stores for some years when the Griston depot became a prison where various memorials to wartime activities can be inspected, possibly under the vigilant eye of CCTV!