U.S. Senator Harry Flood Byrd (June 10, 1887-October 20, 1966) was the pivotal figure of 20th century Virginia politics. He was born in West Virginia, at his mother's ancestral home in Martinsburg. His brother was polar explorer Richard E. Byrd.

Byrd's mother, Eleanor Bolling Flood, was the great-granddaughter of Gen. Elisha Boyd, who built the Martinsburg mansion known as Boydville in 1812. Byrd's great-uncle, Charles James Faulkner of Martinsburg, was U.S. ambassador to France and later an aide to Stonewall Jackson. Byrd was descended on his father's side from the William Byrd family, who were among Virginia's early aristocrats.

Harry Byrd, who grew up in Winchester, Virginia, and later lived in nearby Berryville, made a fortune as an orchard-man and newspaper publisher. He owned newspapers in Winchester and Harrisonburg, Virginia, and in 1907 established the Martinsburg Evening Journal. Having served as governor of Virginia (1925—29), he was appointed to a U.S. Senate vacancy in 1933 and reelected each term thereafter until his retirement in 1965. The "Byrd Machine" ran Virginia politics throughout these years. The conservative Byrd opposed President Roosevelt's New Deal. His son, Harry Byrd Jr., succeeded him in the Senate.