All Saints has a nave of four bays with S aisle and S porch and a vestry on the N side, a broad, aisleless chancel, and a W tower with a low pyramid roof. The chancel arch is 12thc. in its lower parts but was rebuilt, along with the chancel, c.1330. The S nave aisle dates from the late 13thc., and the tower arch is Perpendicular, although the tower itself must be earlier in its lower stages. The porch is 18thc. and of brick, while the remainder of the church is in a rubble mixture of pebble, rough stone and conglomerate. The upper storeys of the tower are rendered and the nave roof is thatched. Romanesque features described are the chancel arch and stones reset in the exterior E wall of the chancel.

In 1066 Rampton was divided between five sokemen of Ely Abbey and one of Edeva the Fair. Ely claimed overlordship of more than 5 hides of the 6 hide vill, but the entire manor was taken by Picot, sheriff of Cambridge, and held from him by Roger. Rampton church was among those given by Picot to Barnwell Priory when he founded it in 1092. Picot's lordship passed to William Peverel his successor, and thence to Maud on Peverel's death in 1147-48. She married Hugh Dover (d.1172) and it was later held by the coheirs of William Peverel.

Presumably the chancel arch was widened in the 14thc., the jambs moved further apart and the present four-centred arch installed.