Circleville is a city in and the county seat of Pickaway County, Ohio, United States. The city is situated along the Scioto River, 25 miles south of Columbus. The population was recorded to be 13,927 in the 2020 census. Circleville is named after its original layout created in 1810, which was based upon the circular Hopewell tradition earthwork within which the city was built. This earthwork measured 1,100 ft in diameter, and was constructed in the early centuries of the Common Era.