Newton Aycliffe is a town in County Durham, England. Founded in 1947 under the New Towns Act of 1946, the town sits about five miles to the north of Darlington and ten miles to the south of the city of Durham. It is the oldest new town in the north of England, and together with the bordering Aycliffe Village (to the south) and the north part of School Aycliffe (to the west), forms the civil parish of Great Aycliffe.