Teesside () is a built-up area around the River Tees in the north of England, split between County Durham and North Yorkshire. The name was initially used as a county borough in the North Riding of Yorkshire.
The number of people employed in this type of work has declined, steel-making (British Steel) and chemical manufacture (Imperial Chemical Industries (ICI)) and have been replaced to a large extent by high technology science development and service sector roles.
