Tarrant County is a county located in the U.S. state of Texas with a 2020 U.S. census population of 2,110,640, making it the third-most populous county in Texas and the 15th-most populous in the United States. Its county seat is Fort Worth. Tarrant County, one of 26 counties created out of the Peters Colony, was established in 1849 and organized the next year. It is named after Edward H. Tarrant, a lawyer, politician, and militia leader.

Fort Worth is a city in the U.S. state of Texas and the seat of Tarrant County, covering nearly 350 square miles (910 km2) into four other counties: Denton, Johnson, Parker, and Wise. According to a 2022 United States census estimate, Fort Worth's population was 956,709, the 5th-most populous in the state and the 13th-most populous in the United States. Fort Worth is the second-largest city in the Dallas–Fort Worth–Arlington metropolitan area, which is the fourth-most populous metropolitan area in the United States, and the most populous in Texas.