The Big Sandy River is a tributary of the Ohio River, approximately 29 mi (43 km) long, in western West Virginia and northeastern Kentucky.
It is formed between Louisa, Kentucky and Fort Gay, West Virginia by the confluence of the Tug Fork and Levisa Fork. It flows generally northwardly in a highly meandering course, between Lawrence and Boyd Counties in Kentucky and Wayne County in West Virginia. It joins the Ohio between Catlettsburg, Kentucky and Kenova, West Virginia, 8 mi (13 km) west of Huntington, West Virginia, at the common boundary between West Virginia, Kentucky, and Ohio.
Two well-known fiddle tunes take their name from the Big Sandy River: "Sandy River Belle" and the "Big Sandy River". Loretta Lynn's "Van Lear Rose" also mentions the river.