The Tees Valley is an area in the North East of England. It can be described as "greater Teesside" and consists of the four unitary authorities created by the breakup of the County of Cleveland in 1996: Hartlepool, Middlesbrough, Redcar & Cleveland, and Stockton-On-Tees along with the borough of Darlington which became a unitary authority in 1997. For ceremonial purposes the areas north and south of the River Tees belong to the counties of County Durham and North Yorkshire respectively (those areas which form part of North Yorkshire, lie within the historic county boundaries of the North Riding of Yorkshire). This arrangement is affirmed by the presence of an appropriate office of the Lord Lieutenancy, representing HM The Queen in these established geographical areas.

Hartlepool is a local government district and borough in the ceremonial county of County Durham, North East England. In 2003 it had a resident population of 90,161. It borders the non-metropolitan county of County Durham to the north, Stockton-on-Tees to the west and Redcar and Cleveland to the south along the line of the River Tees. It is centred around the town of Hartlepool and forms part of the Tees Valley area.
Middlesbrough is a unitary authority and borough in North Yorkshire. It is based on the town of Middlesbrough, which is sometimes considered to spread outside the borough boundaries into the neighbouring borough of Redcar and Cleveland; the borough extends southwards to a semi-rural area. Whilst part of North Yorkshire for ceremonial purposes it is in the region of North East England. It had a resident population in 2001 of 134,855. A 2006 mid-year estimate suggests the Borough to have a population of 138,400 and the urban area to have 147,823 and rising.

The borough of Redcar & Cleveland is a unitary authority in the ceremonial county of North Yorkshire,  consisting of Redcar, Saltburn-by-the-Sea, Guisborough, and small towns such as Brotton, Skelton and Loftus. It had a resident population of 139,132 in 2001, and is part of the Tees Valley economic area. It is represented in Parliament by the barrister Vera Baird (Labour) for the Redcar constituency and by Ashok Kumar (Labour) for the Middlesbrough South and East Cleveland constituency

The borough of Stockton-on-Tees consists of Stockton-on-Tees (population 82,880), and smaller outlying settlements, including Billingham (pop. 36,720), Thornaby-on-Tees, (pop. 23,200) Yarm, Ingleby Barwick and Norton. Durham Tees Valley Airport is also partly within the borough. The Stockton-on-Tees borough accounts for the largest number of residents within the Teesside and Hartlepool urban area. The core of the town was anciently in County Durham, but the borough spilled over the river into Yorkshire. The borough was formed on 1 April 1974, from the Stockton part of Teesside county borough, along with part of Stockton Rural District in County Durham and part of Stokesley Rural District from the North Riding. At that time it was designated a non-metropolitan district of Cleveland.