Demography of the Tees Valley or Teesside metropolitan area of England is recorded with differing definitions.
The first recording of the multiple towns in the area with combined statistics was the 1971 census, during the 1968–1974 borough of Teesside's existence.
The newly formed Tees Valley Combined Authority encompasses 678,000 people and an area of 795 square kilometres (307 sq mi) over its 5 borough councils.
The University of Portsmouth mapped out historic data from 1801 to 1911, using modern Unitary Area land divisions to try and create estimates for what the population for each borough was like.
The created estimates cannot be described as accurate, but use the non profit organisation UK Data Service's collection of sources, specifically the GBHDB.