File:Burnham Westgate, St Mary's church (28531014304).jpg

The church dates from the 14th century and was restored in 1872. There is a west tower, four-bay nave with north and south aisles, three-bay chancel, two-bay north chapel, and south porch. The exterior of the church is mostly Victorian.

The west tower dates from circa 1310 but with a perpendicular top with parapet and battlements containing panels with the arms of William Lexham (died 1500) a Lord of the Manor, and Lady Calthorpe, d. 1511 and also figures illustrating various biblical events. The large brick buttresses were added in the 18th century.

The porch dates from the 15th century and was originally of two storeys. The south door is from the 14th century. The nave has a clerestory, and the arcades have octagonal piers. The chancel was renewed in the 19th century and a north chapel was added. The roofs date from the 19th century.

The east window was designed in 1953 by A. F. Erridge to commemorate the Coronation of Queen Elizabeth II. There is a brass to John Hunteley, d. 1523, but only the wife and children are left intact. In the tower there is a 14th C. stone effigy which was removed from the north aisle in 1823.

The church has a small two manual organ.