There were originally two churches in Lyng, but the other church fell into ruin after the Reformation. Saint Margaret's dates from the 13th century when the tower was built. There is a west tower, aisleless nave, south porch and chancel. The tower is unbuttressed with crocketted pinnacles and a plain parapet. There are five bells. The porch dates from the 15th century, and was originally of two storeys. The nave originally had a north aisle, but this was removed at sometime in the past. This gives the nave a somewhat lopsided appearance. It could have been that the nave was rebuilt on a larger scale, but the chancel never followed.

The chancel was rebuilt in 1912, and parts of the mediaeval chancel arch were retained.

The octagonal font in Purbeck marble is from the early 13th century. The east window has glass from 1968.