English: Mostly 14th & 15th century, built on top of older church. The oldest part of the church is the Norman north door from the 12th century. Tower, nave and chancel are 13th century. The aisle arcades were inserted in the 14th century. The vestry containing the Gage monuments was built between 1556 and 1595. The 14th century chancel arch, has rather crude Capitals.

The Brasses in the church are said to be among the finest in Sussex. They are mainly to the Gage family who have lived at Firle for some 500 years. There are also 3 altar tombs in the North East Chapel including effigies in Alabaster of Sir John Gage and his wife Phillipa.

A window designed by John Piper was installed in 1985 in memory of the sixth Viscount Gage who succeeded in 1912 and died in 1982. The window depicts the tree of life in heavenly Jerusalem.