Portesham, sometimes also spelled Portisham, is a village and civil parish in the county of Dorset in southwest England, situated in the Dorset Council administrative area approximately 6 miles northwest of Weymouth, 6 miles southwest of the county town Dorchester, and 2 miles northeast of the Jurassic Coast World Heritage Site at Chesil Beach. The parish is quite large, covering several outlying hamlets and what were once their manors.