St John's is a flint church with a tall W tower and an aisleless nave and chancel forming a single space within, but separately roofed from the outside. The nave and chancel date fromc.1200 or slightly later, to judge from the N and S nave doorways and plain lancets in the N wall of the chancel and both walls of the nave. The S doorway is protected by a 16thc. brick porch. The square W tower is Perpendicular with diagonal buttresses decorated with simple flushwork. It is patched with bricks and underwent a major restoration in 1983. The nave walls are rendered. The nave doorways are described below, although they are likely to date from the 13thc. rather than the 12thc.

Shadingfield included five holdings in 1086. Godwine, son of Toki held 1 carucate from Roger Bigod. Geoffrey de Mandeville held 1 carucate formerly belonging to Halfdan and 1 carucate formerly held by a free man from Bishop Stigand. Thorth held 20 acres from Ralph Baynard, and William de Noyers held 30 acres on behalf of the king, land formerly held by a free man from Bishop Stigand. No church was recorded in association with these holdings. The existence of so many manors makes it difficult to trace specific holdings. In 1257 Philip Bocland obtained a licence of free warren and the right to hold an annual fair and market here. In 1280-81 Hugo de Berry had a manor here, and in 1281-82 William de Giselham was granted free warren here. In 1306 a manor at Shadingfield was held by John de Brusyard, and at the death of Humphrey de Bohun, 7th Earl of Hereford in 1373 he held seven knight's fees in various Suffolk manors including Shadingfield. It is unknown to which specific Shadingfield manors these scraps of information relate to.

Hundred River Benefice, i.e.: Willingham and Sotterley, Shadingfield, Ellough and Won, Whall, Brampton and Stoven.

The doorways date fromc.1200, probably early 13thc.