The church of St Mary in North Leigh is situated 3 miles NE of Witney. There is a late Saxon tower that was originally central and its W wall shows the blocked round-headed arch and big imposts of the former nave arch, as well as the steep roof lines of both chancel and nave to E and W, thus providing evidence of a substantial pre-Conquest church. It now comprises a chancel with a S vestry, a nave with a S aisle and a S porch, two N chapels dating from the C15th and C17th, and an integral W tower. The early nave was abandoned in or before the late C12th when an aisled nave of two bays was built E of the tower. The chancel was not added until about 1280, its length now exceeding that of the nave. In the C14th, the aisles were extended westwards so that they flanked the tower to S and N, with pointed arches breaching its walls. The church is now best known for the high quality C15th fan vaulting of the Wilcote Chantry Chapel.

The tower retains its original bell openings on all faces, and round-headed windows on S and N faces. On the interior of the tower, the imposts of the former nave arch are again visible on the W wall, as well as arches elsewhere indicating other round-headed openings. Transitional nave arcades to S and N are of two bays, each with pointed arches and a central round Romanesque pier with decorated capitals. There is also an earlier Romanesque doorway that has been reset in the S aisle. There was also once a font (see Comments).

In 1086 North Leigh, assessed at 10 hides, was held by Roger d'Ivri. The chief lordship descended with other d'Ivri possessions as part of the honor of St Valery. The church was given to Eynsham Abbey between 1140 and 1150 by John of St John, lord of the manor of St Valery. It seems that Eynsham failed to retain it. The church passed with the manor of North Leigh until c. 1278, when Edmund, earl of Cornwall, gave it to Hailes Abbey, Glos., that had been founded by his father. The advowson was retained by Hailes until its dissolution, when it passed to the Crown (VCH).

The original Saxon tower was of oblong plan and formerly had a large arch, presumably into the nave, in the W face. Excavation in the mid C19th uncovered traces of foundations W of the tower consistent with a nave of two bays. The external faces of the tower show marks of the gables of early high-pitched roofs to E and W. The nave was presumably abandoned in or before the late C12th, when the aisled nave of two bays was built E of the tower, with the chancel beyond it. In the early C13th the tower was enlarged and a new chancel of two bays was built, leaving the former chancel to serve as the third, unaisled, bay of the nave. In the C14th both nave aisles were extended westwards, and arches were made in the N and S sides of the tower. In the C14th the roofs were reconstructed and the old chancel arch was removed, leaving the responds (VCH). The Benefice of North Leigh is now held in plurality with Cogges and South Leigh.

Although the tower is believed to be of Saxon origin, there is no visible herringbone masonry or long and short quoins. Dating is suggested as 1000-1050 (Sherwood & Pevsner). The only visible decorative work concerns the bell openings on all faces and round-headed windows to E and W. Since similar work was in use for most of the C11th and into the C12th, the decoration is described here (note: similar towers in Oxfordshire are found at Weston-on-the-Green, Ardley, and Spelsbury).

There are precedents for integrally-built Romanesque aisled naves nearby in Oxfordshire, at Church Hanborough and Woodstock. At North Leigh the round piers of the arcades, and the scallop and water-leaf decoration of the capitals, combined with Transitional pointed arches, suggests a late C12th date. However, the reset S doorway with its simple decoration seems more likely to date from c. 1125-1150. Its origin in the church is unknown. It shows a marked resemblance to the blocked one at nearby Wilcote, with cushion capitals and arch decoration of a thick roll moulding, with cylindrical billet under the hood, that they may represent the work of the same mason. Both doorways now show a filled in tympanum and plain lintel. This simple decoration is also consistent with doorways at St Peter’s, Cassington, known to have been consecrated by 1123. However, this does not accord with Sherwood and Pevsner’s dating of the doorway at Wilcote as c.1170.

After a refitting initiated in 1723, the Romanesque font was put to serve as a water-butt in the churchyard and was replaced by a wooden one (VCH). In the mid-C19th the old font was rescued and rechiselled, and it now stands at the W end of the church. Its present form, featuring a square bowl with a series of deeply-cut 'V'-shapes, resting on what appears to be a Perpendicular-era pedestal, is totally unlike Romanesque decoration, and so is not illustrated here. One has to wonder whether the original font was indeed Romanesque, or if this was an antiquarian mis-attribution.

Dedication: The original may have been to The Assumption of the Blessed Virgin Mary (VCH), but this is not confirmed by Arnold-Forster. However, he does not seem to confirm any early ones (see Rousham and Westcote Barton, Oxon.).