Mason County is a county in the U.S. state of West Virginia. As of the 2020 census, the population was 25,453. Its county seat and largest city is Point Pleasant. The county was founded in 1804 and named for George Mason, delegate to the U.S. Constitutional Convention. Before the Civil War, the county was in the State of Virginia. Mason County is part of the Point Pleasant, WV-OH Micropolitan Statistical Area.