This is a list of the most populous urban areas in the United Kingdom based on the 2011 census, as defined by the Office for National Statistics (ONS). As of July 2025, the ONS has not published the equivalent data based on the 2021 census.
Definition
The methodology used by ONS in 2011 is set out in 2011 Built-up Areas – Methodology and Guidance, published in June 2013. When ONS reported the results of the 2011 UK census, it used the term built-up area rather than the term urban area as used in previous censuses. ONS states, however, that the criteria used to define built-up area have not changed: In reporting the 2001 census, the ONS gave a clearer definition of the term "built-up" as follows: ==Most populous==
Most populous
The list below shows the most populated urban areas in the United Kingdom as defined by the Office for National Statistics (ONS) which can be readily referenced at Citypopulation.de. The list includes all urban areas with a population in excess of 100,000 at the 2011 census. ==Map==