Ascott-under-Wychwood is a village about nine miles NW of Witney and six miles S of Chipping Norton. The church lies to the centre of the village and is a rubble structure. The chancel, the S porch and the two lower stages of the W tower were built in the late 12thc; the N and S transepts and the nave were added in the 13thc, and elements of the late Transitional style and the Early English style are clearly visible on the arches of the chancel and the tower, and in the S porch. The N aisle was added to the structure in the 14thc. In 1857, when the church was restored by George Edmund Street, the N vestry was built. The only Romanesque feature here is the nave arcade.

The Domesday Survey records that in 1086 the manor of 'Esthcote' was held by Roger d'Oilly, being his brother Robert tenant-in-chief; it valued £8. The manor of Ascot was held through the 12th century by the d'Oilly family and they were presumably patrons of the church.