Brill is in the W of central Buckinghamshire, ten miles W of Aylesbury and a mile from the Oxfordshire border. It formerly lay within the part of Bernwood Forest known as the forest of Brill by the 13thc. The village is on a limestone hill, and clusters around a junction of minor roads with the church at the centre, the Green to the S of it, and the village square with its 16thc. manor house W of the Green. All Saints is a large, low church with an aisled and clerestoried nave with a 19thc.-20thc. timber S porch, a low W tower and a chancel with a 19thc. N vestry. Construction is of rubble, but the nave and aisles have a grey mortar render. The entire church was rebuilt by J. Oldrid Scott in 1888, incorporating some of the older work. The nave dates from the early 12thc.; part of a blocked round-headed window is still visible above the 19thc. tower arch and the lateral doorways have been reset in the aisle walls. The aisles are wide and low with low-pitched roofs and 4-bay arcades in a Perpendicular style. The N aisle was added in 1839 and the S is Scott's work. The chancel also contains a blocked lancet of c.1100 on the N side. It was extended eastwards by Scott, who installed the old E window of c.1400 above his own new one. The stubby W tower is 15thc. and of rubble. It has a lead spike, mostly concealed by Scott's plain parapet. Photographs are included that show the Norman nave and chancel windows, but only the two nave doorways are described below.

The manor of Brill belonged to Edward the Confessor, and after the Conquest to William the Conqueror. Temporary grants of the whole or parts of it were made from the second half of the 12thc. onwards to various tenants. William de Rochelle held lands here from 1168 to 1178, and in 1204 King John granted the manor to Walter Bustard, a servant of his chapel, in fee farm. This practice continued throughout the reigns of Henry III and the first three Edwards. According to VCH Brill was once a royal borough, but by the mid-13thc. the borough had been subsumed in the manor. The church of Brill was a chapel of Oakley Church from the 12thc. to the 16thc., but since Brill was a royal manor and Oakley lay within its parish boundaries, it was sometimes treated as if the relationship were reversed. According to a charter of Stephen, Brill church had belonged to the priory of St Frideswide, Oxford since the Confessor's time, and in the 13thc. and 14thc. presentations were made to Brill that also included Oakley. It is now part of the Bernwode benefice, i.e. Ashendon, Boarstall, Brill, Chilton, Dorton, Ludgershall and Wotton Underwood.

The doorways have been restored in the resetting and more recently, but enough original stone remains to confirm their form. The fat angle roll and cushion capitals are typical of a date in the first two decades of the 12thc.