Thurleigh is a village and civil parish in north Bedfordshire, England. Thurleigh is about 6 miles (10 km) north of the county town of Bedford. As well as the village centre, the parish is spread across five "Ends", local parlance for a hamlet - Church End, Cross End, Scald End, Backnoe End and Park End, covering an area of about six square miles. The land is undulating boulder clay, ranging in height from 200 ft. to 275 ft. above sea level. A stream runs through the Parish to the south forming a valley which cuts through to the underlying Oxford Clay. The countryside around is in the main used for arable farming. There are only minor roads in the parish, though the A6 and B660 are just a few miles away. These roads however are used as a rat run and a 2007 survey recorded 600 vehicles per hour on Mill Road during the morning and evening rush hours, and 121 HGV's throughout the day.

Excavations have shown evidence the locality was occupied in the Iron-Age, Roman and Saxon periods.[3]

In Domesday of 1086 the Middle English orthography as to both modern 'th' digraph sounds was often in different forms particularly as to this county - the place is LaLega. By 1372 it is Thyrleye. In 1813, Thurleigh, or Thurley, is recorded as being in the Hundred of Willey and the Deanery of Eaton. The scribes were particularly ecclesiastical for the county as Lega is a very Latin-esque form of leigh. The latter is a very common word, rarely used today for meadow or clearing (lea) almost certainly an Anglo-Saxon word perhaps preceded by the definite article, as early written in unrelated prose. Being in the Danelaw however a link to Thor cannot be ruled out.

There was a church here in Saxon times. The current church has some parts still dating from around 1150, and at about that same time a castle was built here.

In 1941, during World War II, an airfield known as RAF Thurleigh was constructed on a plateau just north of the village for RAF Bomber Command. It was used initially for training both RAF and Polish personnel, but in 1942 was turned over to the USAAF and four squadrons of B-17 Flying Fortresses moved in, and over the next three years flew 341 bombing missions. A memorial to these men stands in the village. Events and characters from the USAAF's time at Thurleigh were used as the basis of the novel and film Twelve O'Clock High.

After the war the airfield was used by the Royal Aeronautical Establishment for research and development work. The runway was extended, necessitating the closure of the road between Thurleigh and Keysoe, and the demolition of the hamlet of Backnoe End.

In 1968-71 the Commission for the Third London Airport (the "Roskill Commission") considered Thurleigh as one of its four short-listed sites, along with Cublington, Foulness (later known as Maplin Sands) and Nuthampstead.

The RAE was largely closed down in the 1990s and the site is now used by various commercial enterprises.