Tennessee River, a river in the southeastern United States. It is 652 miles (1,049 km) long. The Tennessee is formed near Knoxville, Tennessee, by the junction of the Holston and French Broad rivers, which rise in the Appalachians. The river flows southwestward across eastern Tennessee, through northern Alabama, and northward across western Tennessee and southwestern Kentucky to the Ohio River at Paducah, Kentucky. Principal cities along the river are Knoxville and Chattanooga, Tennessee. Tributaries include the Clinch, Little Tennessee, Hiwassee, Elk, and Duck rivers.

Dams built by the Tennessee Valley Authority have transformed the once wild and unpredictable Tennessee into a series of long, narrow lakes. The Tennessee-Tom-bigbee (Tenn-Tom) Waterway, beginning at Pickwick Lake in northeastern Mississippi, connects the Tennessee with the Gulf of Mexico at Mobile, Alabama.