Fort Worth is a city in the U.S. state of Texas. It is the county seat of Tarrant County, covering nearly 350 square miles (910 km2) and extending into Denton, Johnson, Parker, and Wise counties. Fort Worth's population was estimated to be 1,028,117 in 2025, making it the 10th-most populous city in the United States. Fort Worth is the second-largest city in the Dallas–Fort Worth metroplex and the fourth-most populous in Texas. The Dallas–Fort Worth metroplex is the fourth-most populous metropolitan area in the U.S., with 8.5 million residents.