All Saints has an aisled nave with aisleless chancel of coarse rubble, and a graceful W tower of ashlar with an octagonal spire, rising to a height of 151 feet. The present building is largely the result of a complete rebuilding, begun in 1470, but some 13thc. features have survived, notably the N doorway, one S aisle window, and a double piscina. The tower was blown down by a gale in 1741, rebuilt in 1748 and again rebuilt in 1879. In 1918 an aeroplane crashed into the spire, which fell on the nave roof, and a rebuilding of spire and roof took place in 1924. The only 12thc. feature is the font.

The manor was originally called Slepe, under which name a church dedicated to All Saints was built by the Abbot of Ramsey, in 970. In 986 the manor was given to Ramsey Abbey by Aethelstan Mannesone. In 1001 a ploughman unearthed a stone coffin containing bones, which discovery was reported to the Abbot of Ramsey. From the evidence of the ploughman's dream about the bones, the abbot determined that they belonged to St Ivo, a 6th-century Persian archbishop. The relic became a focus of pilgrimage at St Ive's Priory (now destroyed), and was ultimately the cause of the change of name. In Domesday, however, the manor is still Slepe, and a church and priest are mentioned.

A similar font is found at All Saints', Conington.