St John's is a remote church standing in flat arable land in SE Suffolk, 6 miles E of Woodbridge. There is no village and no dwellings near the church; the nearest settlement being Tunstall, a mile to the N. Wantisden Hall, a 16thc. brick building, is 0.6 mile S of the church. There has apparently never been a village of Wantisden, and at the beginning of the Second World War the entire area was requisitioned as an airfield: the USAF Bentwaters base. It remained active during the Cold War, and was closed in 1993, but much remains to the W of the church. The church is significant in having one of only two coralline crag towers in the county (the other is at nearby Chillesford), a 15thc. structure with diagonal buttresses and a polygonal S bell stair whose top has been rebuilt without battlements. The nave and chancel are of mixed flint, pebbles and crag rubble. They are 12thc. and from that period they retain a narrow chancel arch, a N chancel window and a S nave doorway. The N doorway is later, plain and pointed, and neither doorway has a porch. The nave has a later medieval SE rood stair, and the other nave and chancel windows date from the 14thc. to 15thc. There is also a 12thc. font, unusual in being constructed of ashlar blocks.

The Domesday Survey provides a picture of an extensive parish with a church, but without a manor and divided among many landholders and overlords. It is striking that Count Alan, Roger de Poitou and the Abbot of Ely all had demesne land here. In 1086, 22 free men held 121 acres and half a church with 20 acres of land from Robert Malet. Also held by Malet were seven acres formerly held by two free men, Alwine and Alflaed, along with a quarter of the church. A further four acres previously held by Aelfric was held by Gilbert from Malet in 1086. Aelfric, Beorhtic and Eadhild, free men, held 11 acres, held by Northmann from Roger Bigod, and Northman also held the last part of the church with ten acres from Bigod. In 1086, Count Alan held 74 acres in demesne that had previously formed two holdings, 14 acres held by Edwin and the remainder held by 16 free men. Roger de Poitou held 40 acres in demesne, held before the Conquest by 14 free men commended to the Abbot of Ely. Twelve acres in Wantisden formed part of the Abbot of Ely's demesne of Sudbourne, and Morwine held two acres from the abbot, before and after the Conquest. Wantisden church, or part of it, or the advowson, was given to the Priory of Austin canons at Butley by Sir Ralph de Glanville, Justiciar of England, as part of the foundation endowment in 1171. In 1235, William d'Auberville, Glanville's great-grandson, gave the priory his third of the church. The house was wealthy and became reasonably large, and it retained Wantisden until the Dissolution in 1538.

Wilford Peninsula benefice, i.e. Alderton, Bawdsey, Boyton, Bromeswell, Butley, Chillesford, Eyke, Hollesley, Iken, Orford, Ramsholt, Rendlesham, Shottisham, Sudbourne, Sutton, Tunstall and Wantisden.

No close comparison can be found for the font in Suffolk, but the form of the scallops associates it with the chancel arch capitals. All of the Romanesque work belongs together, and dates from c.1140-60.