William Mahone (December 1, 1826 - October 8, 1895), of Southampton County, Virginia, was a civil engineer, teacher, soldier, railroad executive, and a member of the Virginia General Assembly and U.S. Congress.
As a civil engineer, he helped build Virginia's roads and railroads in the antebellum and postbellum (Reconstruction) periods of the 19th century.
During the American Civil War, as a leader eventually attaining the rank of major general of the Confederate States Army, Mahone is best known for turning the tide of the Battle of the Crater against the Union advance during the Siege of Petersburg in 1864.
Mahone became a political leader in Virginia, led the Readjuster Party, and helped obtain funding in 1881 for a teacher's school that later grew to become Virginia State University. Small of stature, he was nicknamed "Little Billy".