Millville is an unincorporated community on the Shenandoah River in Jefferson County, West Virginia, United States. According to the Geographic Names Information System, Millville has also been known as Keye's Switch, Keyes Switch and Milville. History The community was named after the Millville Milling Company, the proprietors of a local gristmill. References Unincorporated communities in Jefferson County, West Virginia Unincorporated communities in West Virginia