There is evidence of a Saxon church here with the nave only 13 feet 11 inches wide and the nave walls twice as high as the width. The church was recorded as existing in 1091 and was dedicated to St. Michael by 1190, and probably much earlier. In 1220 there were 3 altars and a tower with 4 bells, but there was no roof on the chancel, probably the result of a fire a little earlier. The churchyard had been recently enclosed to stop beasts fron wandering in. Shortly after 1325 the north chapel was founded and dedicated in hounour of the Blessed Virgin Mary; it was extended in 1393. Shortly after 1350 the south chapel was built by Sir John Bettesthorne, after whom it is named. In the late 13th century the south aisle was widened and in 1430 the north aisle was rebuilt. All this would sem to indicate a fairly prosperous community with landowners spending money on their church.
Between c.1450-6 the church was reconstructed, with the main work in the central area. The chancel roof was raised and the present east window inserted, the chancel arch raised, the nave and arcades rebuilt and the tower of 124 feet rebuilt except for the lower part of the east wall. A magnificent new rood screen was carved and a new font (now on a 19th century base) set up. At this time the floor seems to have been of chalk and men and women sat apart in the church. In 1640 pews were built by William Walter of Maiden Bradley but in 1645 the renowned stained glass was broken by Cromwell's troops. In the West Country the game of fives was often played against the church wall and in Mere this happened on both the south wall (the great fives' place) and also the north wall (the little fives' place) of the tower.
In 1707 the well known yew tree was planted and in 1712 the south aisle was repaired and rebuilt. In Wyatt's restoration of 1856 the church was re-roofed and the Jacobean seats cut down and re-modelled. The church has the royal arms of James I, set up in March 1685 and believed to be the earliest of his reign. Over the doorway of the porch is a statue of the Archangel St. Michael, which dates from 1160, while the churchyard cross has parts of the 1556 cross but was restored in 1898. There is now a peal of 8 bells and the clock and chimes are a World War II memorial. The parents of Rudyard Kipling are buried in the churchyard. The parish registers from 1561, other than those in current use, can be seen in the Wiltshire and Swindon Record Office.