The Tees Valley Line is a name for the railway route between Bishop Auckland and Saltburn via Darlington and Middlesbrough. Also operated on the line are services from Newcastle-upon-Tyne to Middlesbrough and Saltburn via Darlington.
Beyond Bishop Auckland the railway line continues as the Weardale Railway.

Service
All trains along the route are currently operated by Northern Rail, with the exception of TransPennine Express services starting at Middlesbrough and calling at Thornaby. The majority of Northern Rail services are worked by Class 142 units, with occasional services provided by Class 156 units.
Between Darlington and Middlesbrough/Saltburn there is a service running almost every half-hour during the daytime, becoming roughly hourly in the evenings. The service to Bishop Auckland is more sparse. A once weekly service in each direction stops at Tees-side Airport station to service Durham Tees Valley Airport.
The towns and villages served by the line are listed below.

Bishop Auckland
Shildon
Newton Aycliffe
Heighington
Darlington
Middleton St George
Eaglescliffe
Thornaby
Middlesbrough
Redcar
Marske-by-the-Sea
Saltburn