Portishead is a town and civil parish in the North Somerset unitary authority area, in the county of Somerset, England. With a populatio…Portishead is a town and civil parish in the North Somerset unitary authority area, in the county of Somerset, England. With a population of 26,366 at the 2021 Census, the town is located on the Severn Estuary opposite Cardiff and Newport in Wales. The town is 8 miles to the west of Bristol and 18 miles northeast of Weston-super-Mare.