The church, heavily restored by Sir Arthur Blomfield in 1876, incorporates some 12thc. fabric, namely the NW tower, one and a half bays of the N nave arcade and a blocked S doorway. Blomfield's extensive restorations included the removal of the dividing wall between the parish and priory churches (see below) and the reconstruction of the E end of the arcade. Romanesque sculpture is found at the W end of the nave arcade.

Easebourne is not mentioned in the Domesday Survey, but a church was erected in the course of the 12thc. A priory of Augustinian canonesses was founded by one of the de Bohun family before 1238 (Nairn and Pevsner, 212) or c.1238 (church guide book), and was endowed with the parish church of Easebourne and its chapel-of-ease at Midhurst. The chancel and E end of the old nave became the priory church, and were closed off from the remainder of the building, comprising the W tower, the W end of the nave and the newly enlarged N aisle, which now served as the parish church. Conventual buildings were erected on the S side of the church. At the Reformation the priory was given to Sir William Fitzwilliam, owner of Cowdray.

The scallop capitals of the nave arcade date from the second half of the 12thc. and may be contemporary with the font. Nairn and Pevsner date the font to the late 12thc.