Fort Bend County is a county located in the U.S. state of Texas. The county was founded in 1837 and organized the next year. It is named for a blockhouse at a bend of the Brazos River. The community developed around the fort in early days. The county seat is Richmond. 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.

The Brazos River, called the Río de los Brazos de Dios by early Spanish explorers, is the 14th-longest river in the United States at 1,280 miles (2,060 km) from its headwater source at the head of Blackwater Draw, Roosevelt County, New Mexico to its mouth at the Gulf of Mexico with a 45,000-square-mile (116,000 km2) drainage basin. Being one of Texas' largest rivers, it is sometimes used to mark the boundary between East Texas and West Texas.