Robert Carlyle Byrd (born Cornelius Calvin Sale Jr.; November 20, 1917 – June 28, 2010) was an American politician and musician who served as a United States senator from West Virginia for over 51 years, from 1959 until his death in 2010.

A Democrat, Byrd also served as a U.S. representative for six years, from 1953 until 1959.