The Manor of Debden dates back to before the Norman Conquest, but the parish church of St Mary the Virgin and All Saints dates from the thirteenth century. The Chiswell family acquired Debden Hall in 1715. The direct male line died out in 1772 and Richard Muilman, whose mother had been a Trench Chiswell, inherited the estate, and took the Trench Chiswell name. It was he who undertook the major renovations and refurbishments of Debden Church, including the construction of the present chancel, during the late 18th century. His only child, a daughter, married Sir Francis Vincent and they and their descendants lived at Debden Hall. The coffins in the vault belong to Vincent family members. A significant new addition was completed in early 2000 to mark the second millennium.

1. South Porch
The porch was added in about 1340, when the south aisle was rebuilt.

2. Font
The font was designed by Richard Holland (a cousin of the architect, Henry Holland) who also designed the 18th century chancel. The font is made of Coade stone. It was exhibited to the King at Buckingham Palace and illustrated in the Europe Magazine in 1786, shortly after its manufacture. It cost £50.

3. Nave
The pillars at either side of the nave are the oldest part of the church. The north side was built about 1220 and the south side some twenty years later. The south aisle was rebuilt in 1340 and the north aisle rebuilt on old foundations some 100 years thereafter. The finely worked and co-ordinated hassocks (kneelers) were made between 1968 and 1972.

4. Organ
The first pipe organ was destroyed by fire in 1878. It was replaced in 1880 and again in 1947. The latter organ, which was underpowered, was taken out of service in 2016 and an electronic instrument installed in its stead.

5. North Aisle
The War Memorials recording those from Debden who died in the First and Second World Wars are on the north wall. The adjacent window is in memory of the Fisher family. Frederick Fisher (Rector 1890-1908) was the last Rector to live in the old Rectory, now Debden Manor. The doorway at the east end of this aisle was created in 2000 to give access to the New Room directly from the nave.

6. New Room
The New Room and vestry were designed by Purcell, Miller, Tritton and Partners and built by Cadman Group in 2000 to mark the second millennium of the birth of Jesus Christ and to provide a room for church meetings and activities. The building, which cost £200,000, was entirely funded by 70 families living in the village or worshipping at Debden Church.

7. Chancel and Chiswell Chapel
The church was originally built with a cross aisle and steeple between the nave and chancel. The steeple fell down in 1698 and was rebuilt only to fall again in 1717, when parts of the church were used as a school. Major repairs were made to the whole church in 1786, but the chancel was completely demolished in 1787 to make way for a new vault to house the Chiswell coffins. Both the vault and the chapel behind the altar were designed by Richard Holland. The chapel, a lovely example of Strawberry Hill Gothic, houses the monument to Richard Muilman Trench Chiswell. The plaques, inside and outside the Chapel, are of Coade stone, like the font. The stained glass window was made by Gibbs and Howard and installed about 1900.

8. South Aisle
The South Aisle was rebuilt around 1340. The painted glass window is a memorial to Richard Muilman Trench Chiswell and was probably originally in the Chiswell chapel behind the altar. It was moved to its present position about 1900. The large chest is a fine example of a 14th century tomb chest. It is made of 3inch oak cross-bound with iron. The lid is constructed so it may be opened without jarring or noise. The chest is empty.

9. Steeple
Following the collapse of the original steeple, a new steeple designed by the ‘ingenious Mr Essex, architect of Cambridge’ was erected at the west end of the church in 1790. This was in danger of collapse in 1930, and was replaced by the present steeple, which houses two bells. The present steeple was the gift of Mr and Mrs Bland. It is best seen from outside the church at the west end.