The church of ST. JOHN THE BAPTIST, Windlesham, consists of a modern chancel with a north vestry and south chapel, a nave with north and south aisles, a south porch, and a south-western tower. The south chapel and aisle are the chancel and nave of a small church, the date of which is given on a board in the tower, which bears the inscription:
'Burnt by lightning in 1676. Rebuilt 1680 John Atfield Richard Cotherell.' The tower dates from 1838, and, like the rest of the church, is of brick. The 17th-century walls are faced with a chequer of black and red bricks; the aisles have projecting stone quoins. In the south wall of the old nave are four windows of Gothic style, two of three lights in 15th-century style with square heads, and two of late 13th-century style with a quatrefoiled circle over the trefoiled lights. They are in part modern, in part old work reset. The porch has small balustered openings on either side.
The roofs, seating, and fittings throughout are modern, and of no particular interest. The sanctuary has been somewhat elaborately decorated in recent years, and has a high dado of marble and mosaic. Preserved in a glass case in the nave is a chained copy of Jewel's Apology, found in the floor of the tower at the time of the enlargement of the church.
There are no monuments of any interest.
The church plate is a silver-gilt set given by H.R.H. the Duchess of Gloucester in 1841, and consists of two cups with paten covers of 1841, a paten of 1840, a flagon of the same date, an almsdish undated, but part of the set, and a cup of 1896.
The first book of the registers contains baptisms from 1677 to 1689; a second, all entries from 1695 to 1747; a third, baptisms and burials from 1749 to 1783, and marriages from 1749 to 1753; a fourth, baptisms from 1783 to 1810; a fifth, burials from 1793, and baptisms from 1810 to 1812. There are also two printed marriages and banns books from 1754 to 1802, and from 1802 to 1812.