Bentley is a village in the East Hampshire district of the county, 10 miles SE of Basingstoke, on the N side of the A.31 between Alton and Farnham. St Mary's is on rising ground on the N edge of the village and consists of a nave with a W tower, N and S aisles and a S porch, and a chancel with N and S chapels. Construction is of flint, partly rendered with brick for the upper part of the W tower. The oldest part is the chancel, built in the 12thc, to which the N chapel, entered through a 2-bay arcade, was added later in the century. The S chapel was a 13thc addition. The nave predates the 15thc and remained aisleless until 1835 when a S aisle was added. This became ruinous by 1890, when it was replaced and a new N aisle added by Henry Woodyer. The tower was originally 12thc, and the brick upper storeys date from the 18thc. The timber S porch is modern, and a church hall was added on the N side of the church in 2015. Romanesque features descibed here ar the N chancel chapel arcade, the piscina and the Purbeck font.

The manor and liberty of Bentley belonged to the Bishop of Winchester from an early date, perhaps as early as the 8thc. The grant was confirmed by Edward the Elder in 909, and by King Edgar at the end of the 10thc. He was holding Bentley as a manor of 10 hides in 1086, and Osbern de Ou was holding 1 hide and 1 virgate from home, and William 1 hide and a half at that time. The manor remained with the bishop throughout the Middle Ages. The church was a dependent chapelry of Farnham throughout the Middle Ages.

The piscina must date from earlier in the 12thc than the N chapel arcade, but that could have been added at any time between the mid-12thc and the end of the century, the type of capital being so long-lived and prevalent in Hampshire. Likewise the imported Purbeck font could date from any time after c.1170 when widespread exports began.