Holwell is a village and civil parish in the county of Dorset in southern England, situated in the West Dorset administrative district approximately 5 miles (8.0 km) south-east of Sherborne. It is sited on Oxford clay in the Blackmore Vale. Its name derives from the Old English hol and walu, meaning a bank or ridge in a hollow. In the 2011 census the parish had a population of 369 and is part of the Cam Vale electoral ward. Until 1844 Holwell was an exclave of Somerset, being part of the parish of Milborne Port.