Smithville (also Smithton) is an unincorporated community in southern Ritchie County, West Virginia, United States. It lies along West Virginia Route 47 south of the town of Harrisville, the county seat of Ritchie County. Its elevation is 686 feet (209 m). Although it is unincorporated, it has a post office, with the ZIP code of 26178. The North Bend Rail Trail passes through the community.