The Clarence Railway was an early railway company that operated in north-east England between 1833 and 1853. The railway was built to take coal from mines in County Durham to ports on the River Tees and was a competitor to the Stockton and Darlington Railway (S&DR). It suffered financial difficulty soon after it opened because traffic was low and the S&DR charged a high rate for transporting coal to the Clarence, and the company was managed by the Exchequer Loan Commissioners after July 1834. An extension of the Byers Green branch was opened in 1839 by the independent West Durham Railway to serve collieries in Weardale.