St Mary's stands to the south of a motte ringed by a ditch. It has a clerestoreyed, aisled nave with three-bay arcades. The aisles have been extended westwards alongside the west tower. The chancel was rebuilt in 1840 with a north chapel now housing the organ, and a north vestry to the east of that. The nave arcades are late 12thc., although the pointed, chamfered arches appear later than the piers and their capitals. Both arcades have 19thc. labels with figural label stops. The lower part of the tower and its arch, and the extensions to the aisles are c.1300, and the upper storeys of the tower and the nave clerestorey are Perpendicular. The S nave doorway is under a porch. Construction is of ashlar and roughly shaped, coursed stone. There was a general restoration in c.1880 by E. B. Law. The only Romanesque work is in the nave arcades.

Neither the church nor the castle is mentioned in Domesday. At this time Culworth was held by Osbern from Geoffrey de Mandeville.

Benefice of Culworth with Sulgrave and Thorpe Mandeville and Chipping Warden with Edgcote and Moreton Pinkney.

The piers and their capitals belong to the years around 1200, but the arches were replaced in the later 13thc.