The church has a chancel with attached N vestry, nave with N and S aisles and S porch, and a W tower. The original 11thc. or 12thc. church would have comprised nave and chancel only. The N and S arcades were built at the end of the 12thc. The chancel is 13thc. with later alterations, while the chancel arch is 14thc. as is the W tower which was built in 1380. The clerestory was added in the 15thc. and the aisles were also rebuilt at this time. The vestry is 17thc.

In the 19thc. the church was restored by Eden Nesfield who also built the S porch and restored most of the external stonework. At this time the N aisle was rebuilt, the vestry was enlarged and the organ chamber added. The chancel arch was also rebuilt. The chancel has traces of two 12thc. windows in the E wall flanking a 14thc. window. Late 12thc. (Transitional) sculpture survives on the capitals of the N and S arcades. The building material is knapped flint, The ashlar quoins of the original chancel are visible in the E wall.

Prior to the Conquest the two manors in King's Walden, one of which presumably included the advowson, were held respectively by Leueva and Asgar's widow of Earl Harold. At the time of DS the former was held directly by the king and the latter continued to be held by Asgar's widow. Both manors are named King's Walden.

Pevsner comments on the overlap between Romanesque and Early English styles demonstrated by the sculpture of the nave piers. The capitals probably date to the 1170s or 1180s. See also Kimpton.