A Norman Church on the present site is first mentioned 1106, but only the North and South doors and font remain, reused in a subsequent construction. The present chancel belongs to the decorated period and was built around 1340, with a south aisle being added some decades later.
With the exception of the chancel the Church was rebuilt in the perpendicular style from just before 1500 until about 1540 when the tower with the pinnacles was completed. In 1848 the Church was restored and improved under the supervision of Francis Niblett. The walls of the chancel were raised and the roof replaced. The tall box pews were replaced with the current pews but utilising wood salvaged from the old pews, with the addition of machined ends and rails.
An illustrated guide to the church is available to those who visit for a small consideration.
Information about Monumental Inscriptions in St Mary's Church can be found in the Thornbury roots website.