A large church, mainly 14thc. in date, with an aisled nave, transept, crossing tower and square chancel. Nairn and Pevsner suggest that the nave may have 11thc. origins, although there is no visible evidence of this. The church contains a Romanesque font and a fragment of a cross shaft, the latter of uncertain date.

Harting is mentioned in the Domesday Survey, but not a church, although 'St Nicholas' clergy hold 6 hides of this manor's land'. It was altered after a fire in 1576 (see roofs, dated 1577 on trusses). The Caryll Chapel was built on the S side of the chancel in the 17th century, but became ruinous in the 19th century. The church was restored in 1852 and 1870. The 19th-century porch was rebuilt in 1938.

Nairn and Pevsner date the font to the 13thc., presumably because the arches have trefoiled heads while those of most arcaded Sussex marble fonts have simpler, rounded heads.