Barnard Castle in the context of Silver Swan (automaton)

County Durham, officially simply Durham, is a ceremonial county in North East England. The county borders Northumberland and Tyne and Wear to the north, the North Sea to the east, North Yorkshire to the south, and Cumbria to the west. The largest settlement is Darlington.

The county has an area of 2,676 square kilometres (1,033 sq mi) and had a population of 894,025 in 2024. The centre and east of the county are more densely populated than the west, and the major settlements include Hartlepool on the south-east coast, Stockton-on-Tees in the south-east, Darlington in the south, and the city of Durham in the north-centre. Stockton-on-Tees is part of the Teesside conurbation, which extends into North Yorkshire. Barnard Castle is the largest town in the west of the county. For local government purposes the county comprises the unitary authority areas of County Durham, Darlington, Hartlepool, and part of Stockton-on-Tees. Durham County Council is part of the North East Combined Authority, and the councils of the other three areas are part of the Tees Valley Combined Authority. The part of Tyne and Wear south of the River Tyne was historically part of County Durham, and the part of Durham south of the River Tees was historically part of the North Riding of Yorkshire.