St Andrew's has a nave with aisles, the N arcade of four bays dating from c.1170-80, the S equally long but of three bays and early 13thc. The roof was raised and a clerestorey added in the 15thc. The W tower is 13thc, and later in that century N and S transepts were added. The chancel was rebuilt at around the same time. In 1840-41 the church was restored, the chancel arch rebuilt and a south porch added. The tower was underpinned and thoroughly restored in 1902-3, and the rest of the church in 1904-5. Construction is of stone rubble with Barnack dressings, ashlar in the transepts, and rendered brick for the clerestorey. 12thc features described here are the N nave arcade, the S doorway and the font.

A confirmation of the grant of lands to Peterborough (Medeshamstede) by Wulfhere, king of Mercia, in 664 includes Alwalton, but this is generally thought to be a post-Conquest forgery. No church is mentioned in 1086, but the manor of 5 hides was held by the Abbot of Peterborough. The church and its rector are recorded in the Hundred Rolls of 1279; the manor was still held by the Abbot of Peterborough.

Benefice of the Ortons, Alwalton and Chesterton.

Pevsner suggests that the later form of pier 3 represents a lengthening of the N arcade in the early 13thc (with the original W respond reused further W) and this seems entirely reasonable, especially in view of the fact that there are only two chamfer stops (which he oddly omits). These are careful productions of 1170-80. The stylistic mismatch between the jambs and arch of the S doorway, and the trimming of the chevron voussoirs suggests that the arch was originally round, and that the doorway was remodelled in pointed form with new jambs when it was reset in the 13thc aisle.