Portsmouth is a city located in Scioto County Ohio. It is also the county seat of Scioto County. With a 2020 population of 19,944, it is the 86th largest city in Ohio and the 1870th largest city in the United States . Portsmouth is currently declining at a rate of -0.53% annually and its population has decreased by -1.39% since the most recent census, which recorded a population of 20,226 in 2010. Portsmouth reached it's highest population of 42,560 in 1930. Spanning over 11 miles, Portsmouth has a population density of 1,858 people per square mile.
The average household income in Portsmouth is $50,345 with a poverty rate of 36.48%. The median rental costs in recent years comes to $606 per month, and the median house value is $78,400. The median age in Portsmouth is 36.1 years, 32.5 years for males, and 37.8 years for females.