Portsmouth is a city located in Scioto County in southern Ohio, United States, serving as the county seat. It sits on the north bank of the Ohio River, approximately 41 miles south of Chillicothe, positioned just east of where the Scioto River meets the Ohio River. The city lies directly across the river from Kentucky.
According to the 2020 census, Portsmouth had a population of 18,252 residents. The city functions as the principal city of the Portsmouth micropolitan area.