The Little River is a river in Central Texas in the Brazos River watershed. It is formed by the confluence of the Leon River and the Lampasas River near Little River, Texas in Bell County. It flows generally southeast for 75 miles (121 km) until it empties into the Brazos River about 5 miles (8.0 km) southwest of Hearne, at a site called Port Sullivan in Milam County. The Little River has a third tributary, the San Gabriel River, which joins the Little about 8 miles (13 km) north of Rockdale and five miles southwest of Cameron. Cameron, the county seat of Milam County and the only city of any significant size on the Little River, was established in 1846.

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.