Darlington is a unitary authority area in the ceremonial county of County Durham, north-east England. It borders the non-metropolitan county of County Durham to the north and west, Stockton-on-Tees to the east and North Yorkshire to the south along the line of the River Tees. The urban centre of the borough is the town of Darlington and is a major component of the Tees Valley economic area. In 2011 it had a resident population of 106,000.