St Leonard's has an aisled and clerestoreyed nave with arcades and aisle windows of c.1300 and the clerestorey a Perpendicular addition. The chancel is substantially of c.1300, but much restored. The W tower is 12thc. with plain round headed lancets at ground storey level, but bell-openings dating from the 13thc. The W doorway is also early 13thc., and in front of it is a Perpendicular west porch. The N nave doorway is late 12thc. but blocked: the S doorway is 13thc. and protected by a porch. Construction is of ashlar with a rubble W tower. There was a restoration in the 1870s and another in 1881-82 by J. M. Townsend. Romanesque interest centres on the boldly carved early 12thc. font and the N doorway.

Aston le Walls was held by Mauger from Geoffrey de Mandeville in 1086. No church was recorded at that time.

Benefice of Byfield with Boddington and Aston le Walls.

The closest comparison for the font is the more elaborate and probably later font at Braybrooke, which is similar in its form, its use of a different design for each face, and in the knotwork motif on the E face here. Foliage similar to that on the W face of the font (described by Pevsner as 'a very asymmetrical Tree of Life') is found in conjunction with intersecting arcading on the font at Magdalen College, Brackley. The Brackley font also has dogtooth, however, and must be considerably later than this one, where the diapering and knotwork suggest an earlier date.