The see is based in the City of Chichester where the bishop's seat is located at the Cathedral Church of the Holy Trinity.

The episcopal see at Selsey was founded by Saint Wilfrid, formerly Bishop of the Northumbrians, for the Anglo-Saxon Kingdom of Sussex in the late 7th century.

He was granted land by Æthelwealh of Sussex to build a cathedral at Selsey.

However, shortly afterwards Cædwalla of Wessex conquered the Kingdom of Sussex, but he confirmed the grant to Wilfrid.

Nine years after the Norman conquest, in 1075, the Council of London enacted that episcopal sees should be removed to cities or larger towns.