Denton County is located in the U.S. state of Texas. As of the 2020 census, its population was 906,422, making it the seventh-most populous county in Texas. The county seat is Denton. The county, which was named for John B. Denton, was established in 1846. Denton County constitutes part of the Dallas–Fort Worth metroplex. In 2007, it was one of the fastest-growing counties in the United States.