Upshur County is a county in the U.S. state of West Virginia. As of the 2020 census, the population was 23,816. Its county seat is Buckhannon. The county was formed in 1851 from Randolph, Barbour, and Lewis counties and named for Abel Parker Upshur, a distinguished statesman and jurist of Virginia. Upshur served as United States Secretary of State and Secretary of the Navy under President John Tyler.