The village of Radley stands in a loop of the Thames that forms the boundary between the traditional counties of Berkshire (to the W) and Oxford (to the E). The village is now on the NE outskirts of Abingdon, and at the northern edge of the village stands the church and Radley College. St James's church consists of a nave with a W gallery, a S aisle and S transept (housing the organ), a chancel and a W tower. The S aisle is separated from the nave by five bays of tall wooden piers that carry longitudinal arched braces instead of arches. It was restored and reseated by J. O. Scott in 1900-03. The font is 12thc., as is a corbel discovered during the 1900-03 restoration on the NE of the chancel arch.

Radley is not noted by name in the Domesday Survey, but VCH argues convincingly that it was included in Abingdon Abbey's large demesne manor in Abingdon itself, called Bertune in Domesday. This was assessed at 40 hides in 1086. It remained a possession of the abbey until that foundation was dissolved in 1538. The church was described as a chapel to St Helen's, Abingdon in 1284, and as such it was in the gift of the abbot. It now belongs to the United Benefice of Radley and Sunningwell.

The font is one of the most elaborate in the county, and while other elaborate arcaded fonts survive at Avington, Enborne, Clewer and St Agnes Spital, Windsor, none of them is very close to this. What impresses most about it is the varied forms of its fictive capitals and bases; micro-architectural forms rarely found at this early period. These, and the high degree of elaboration, point to a date in the 1170s.