Tucson (/ ˈ t uː s ɒ n, t uː ˈ s ɒ n /; Spanish: Tucson, O’odham: Cuk-Ṣon) is a city in and the county seat of Pima County, Arizona, United States, and is home to the University of Arizona. It is the second largest city in Arizona behind Phoenix , with a population of 542,629 in the 2020 United States census , [6] while the population of the entire Tucson metropolitan statistical area (MSA) is 1,043,433. [7]