Denton is a city in the U.S. state of Texas and the county seat of Denton County. With a population of 139,869 as of 2020, it is the 20th-most populous city in Texas, the 177th-most populous city in the United States, and the 12th-most populous city in the Da…Denton is a city in the U.S. state of Texas and the county seat of Denton County. With a population of 139,869 as of 2020, it is the 20th-most populous city in Texas, the 177th-most populous city in the United States, and the 12th-most populous city in the Dallas–Fort Worth metroplex.