Dorset (/ˈdɔːrsɪt/ DOR-sit; archaically: Dorsetshire /ˈdɔːrsɪt.ʃɪər, -ʃər/ DOR-sit-sheer, -shər) is a ceremonial county in South West England. It is bordered by Somerset to the north-west, Wiltshire to the north and the north-east, Hampshire to the east, the Isle of Wight across the Solent to the south-east, the English Channel to the south, and Devon to the west. The largest settlement is Bournemouth.
The county has an area of 2,653 km (1,024 sq mi) and had an estimated population of 798,914 in 2024. A conurbation on the south-east coast contains the towns of Bournemouth, Christchurch, and Poole. The remainder of the county is largely rural, and its principal towns are the seaside resort of Weymouth in the south and Dorchester in the south-centre. For local government purposes Dorset comprises two unitary authority areas: Bournemouth, Christchurch and Poole and Dorset. The county did not historically include Bournemouth and Christchurch, which were part of Hampshire.