Scioto County is a county located in the south central region of the U.S. state of Ohio. As of the 2010 census, the population was 79,499. Its county seat is Portsmouth. The county was founded March 24, 1803 from Adams County and is named for an Indian word referring to deer or deer-hunting.Scioto County comprises the Portsmouth, OH Micropolitan Statistical Area, which is also included in the Charleston-Huntington-Ashland, WV-OH-KY Combined Statistical Area. It is located at the confluence of the Scioto and Ohio rivers.GeographyAccording to the U.S. Census Bureau, the county has a total area of, of which is land and (1.0%) is water. Many parts of Scioto County are heavily forested, especially in the western half of the county with Shawnee State Park.