Fort Bend County is a county located in the U.S. state of Texas. According to 2019 census estimates, its population was 811,688 and Texas's 10th-most populous county. In 2015, Fort Bend County became Texas's wealthiest county, with a median household income of $95,389 and a median family income of $105,944, surpassing Collin and Rockwall Counties since the 2000 census. The county seat is Richmond, and the largest city located entirely within the county borders is Sugar Land. The largest city by population in the county is Houston; however, most of Houston’s population is located in neighboring Harris County.