Pagham Harbour is a 629-hectare (1,550-acre) biological and geological Site of Special Scientific Interest on the western outskirts of Bognor Regis in West Sussex. It is a Geological Conservation Review site, a Nature Conservation Review site, a Ramsar site, a Special Protection Area and a Marine Conservation Zone. An area of 599.1 hectares is a Local Nature Reserve.

Pagham is a coastal village, Anglican parish and civil parish in the Arun district of West Sussex, England, with a population of around 6,100. It lies about two miles to the west of Bognor Regis.