The parish is bounded to the north by Cockley Brook, a tributary of the River Dorn.

The Domesday Book records that by 1086 Gilbert de Magminot, Bishop of Lisieux held Westcott Manor.

It remained in his family until early in the 12th century when Gilbert's grand-niece Alice Maminot was married to Ralph de Keynes.

[2] There is archaeological evidence that by at least the 11th century there was an Anglo-Saxon stone church at Westcott Barton, which was originally dedicated to St Edmund the Martyr.

[5] In the 14th and 15th centuries the chancel and north wall of the nave were rebuilt, the west tower and battlemented south porch were built[2] and the wooden rood screen was installed, all in Perpendicular Gothic style.

In 1855–56 the gallery was removed and the church was restored under the direction of the Oxford Diocesan Architect G.E.

[4] In the churchyard just south of the church are a 15th-century tomb chest that has a quatrefoil at either end, and the base and steps of a late medieval stone cross.

In 1538, in the Dissolution of the Monasteries, the Abbey surrendered all its property to the Crown, which in 1557 sold the advowson of Westcott Barton to a secular buyer.

Earthworks indicating the sites of buildings survive to the west, south and east of the churchyard.

[2] The main road between Bicester and Enstone traverses the parish from east to west.