Barnham is listed in the Domesday Book of 1086 as having a mill, a church and 24 households, and woodland, plough land and meadows.

[6] It retains some of its rich agricultural history, having had very little woodland for many centuries, and gently rolling cereal fields and pasture instead.

[7] The parish church, dedicated to St Mary, was given to the Abbey of Lessay in Normandy in 1105 and later passed to Boxgrove Priory.

Another public house served the village from the early 20th century until 2010: The Barnham Bridge Inn which closed when the brewery was taken into administration.

St Mary's Church represents the heart of 'Old Barnham', but when the railway station and junction for Bognor Regis were built approximately one mile north of the church, the focus of the village shifted as businesses built premises adjacent to the station and this was followed by housing developments centred on this location.