An urban agglomeration is defined as "a continuous urban spread constituting a town and its adjoining outgrowths, or two or more physically contiguous towns together with or without outgrowths of such towns".
An urban agglomeration must consist of at least a statutory town and its total population (i.e. all the constituents put together) should not be less than 20,000.
Below is a list of urban agglomerations in the state of Tamil Nadu, with a population of 1 lakh and above based on the 2011 census of India.
[1] Cities in bold are declared Municipal corporations.
2011