Addison is an incorporated town in Dallas County, Texas, United States. Addison is situated to the immediate north of the city of Dallas, with a 2020 census population of 16,661. Addison and Flower Mound were the only two Texas municipalities labeled "towns" with a population greater than 10,000 at the 2010 census; since then the municipalities of Prosper and Trophy Club—also identifying as towns—have also exceeded 10,000 in population estimates.