File:St Mary's church, Westwell, Kent (14278536231).jpg

There has been a church at Westwell since Saxon times, the church was an "appendage" to the Manor of Westwell, and was part of the possession of Christchurch Canterbury. The majority of the church was built in the mid 13th century. It consists of nave, chancel, porch and west tower. The north and south aisles were added to the nave in the 14th century. There is a 15th century south porch with an ancient oak door. The font is 12th century, made of Bethersden marble, now standing on a modern support. It was once discarded and used as in a farmyard. The tower arch has female corbel heads, and an ancient oak ladder leads up into the Belfry which has four bells. Some stonework in the tower could date back to pre-Norman times. The nave has four bays on round and octagonal piers. There is an unusual triple chancel arch with three trefoil arches springing from slender cylindrical shafts 17 feet high. the chancel contains 14th century choir stalls with carved poppy heads. The south wall has two piscinae and a sedilia from around 1330 with a carved head above. Originally there was a Rood screen which was in position as late 1719, the staircase in the wall is still present.

The east window of the chancel contains a 13th century Jesse tree from 1240-1250. The upper half of the lancet window is original with pot metal colouring. The lower half was restored in 1960 using scraps of ancient glass. There are other sections of mediaeval glass, one in the east window of the north Chapel dates from 1397 and depicts two Shields. The arms of Edward the Confessor and Richard II, and also Anne of Bohemia and Edith, wife of Edward the Confessor. Other glass in the church is 19th-century, dedicated to members of the Sharpe and Gascoigne family. There is a new millennium stained-glass window designed by Alexandra le Rossignol in the south wall of the nave.

At the east end of the nave is a 14th century incised floor slab, originally inlaid with brass, now long gone. This was to Master John de la More, circa 1305.

The church underwent various repairs in the 19th century, and in 1906 the tower was struck by lightning and caught fire. The fire brigade extinguished the flames preventing excessive damage.