Roanoke River, river rising in the Appalachian Valley in Montgomery County, southwestern Virginia, U.S., and flowing in a southeasterly direction for 380 mi (612 km) into Albemarle Sound, on the Atlantic coast of North Carolina. It drains an area of 9,580 sq mi (24,810 sq km). Just north of the Virginia–North Carolina boundary it joins the Dan River, its principal tributary; above the junction the river was formerly known as the Staunton.
The Roanoke is navigable for small craft for 112 mi from its mouth to Weldon, N.C., which lies just below the Fall Line near Roanoke Rapids, N.C. Ships with a draft of up to 12 ft (3.65 m) can reach Plymouth, N.C., 6 mi above the mouth. In 1829 the Weldon Canal, 12 mi long, was opened as a passage around the rapids, but it was abandoned in 1850. The river is impounded by a series of dams: Smith Mountain and Leesville below Roanoke, Va.; John H. Kerr Dam below Clarksville, Va.; and Roanoke Rapids Dam, which impounds Lake Gaston.