The building has "benefited from sympathetic restoration"[2] over the centuries—including a series of works by prominent architects Paley and Austin in the Victorian era, and internal renovation after a fire in the early 21st century.

[3] After the Norman Conquest in 1066, monks from Grestain Abbey, a Benedictine monastery in Normandy, took possession of the land around the village of Wilmington.

[7] A vast yew tree in the churchyard, scientifically dated as 1,600 years old and with a girth of 23 feet (7.0 m), suggests that the site was considered sacred to pre-Christian people.

[4] The existence of a "strange ... gargoyle-like" figure known as the Wilmington Madonna—originally on the outside wall but now preserved in the chancel—may also be evidence of pagan worship in the area.

[7] During the 13th century a north chapel or transept was added towards the east end of the nave, and a two-bay south aisle was built.

[8][10] Around the same time, diagonal buttresses were added at the east end—possibly because the insertion of new windows in the chancel had weakened the walls.

There is evidence of blank arcading around some of the windows—a feature also seen at St Michael and All Angels Church in nearby Little Horsted.

[4] The font dates from the 14th century, and consists of plain square bowl supported by a central column and four corner shafts.

[5][10] An unusual feature from the church's earliest days is a set of inward-facing stone seats attached to the inner walls of the chancel.

[17] It forms part of the united benefice of Arlington, Berwick, Selmeston-with-Alciston and Wilmington, which covers the Anglican churches in those five downland villages.