Arnoldsburg (also Arnoldsburgh) is an unincorporated community in Calhoun County, West Virginia, United States. It lies along U.S. Route 33 at the point where West Virginia Route 16 heads southward; it is several miles south of the county seat of Grantsville. Its elevation is 738 feet (225 m). The West Fork Little Kanawha River flows through the community. It has a post office with the ZIP code 25234. Arnoldsburg derives its name from Charles Arnold, a local schoolteacher.