Circleville was founded in 1810. It derived its name from the circular portion of a large Hopewell culture earthwork upon which it was built. The original town plan integrated Circleville into the preexisting land with a street layout of concentric circles. An octagonal courthouse stood directly in the center.
Dissatisfaction rose with Circleville's layout, however, and in 1837, the Ohio General Assembly authorized the "Circleville Squaring Company" to convert it into a conventional grid. By 1856, this had been completed in several phases. No remaining traces of the original earthworks remain, though a few old buildings retain curved walls that were part of the original circular layout.
Circleville is located at (39.602990, -82.939272).
According to the United States Census Bureau, the city has a total area of 6.7 square miles (17.5 km²), of which, 6.6 square miles (17.1 km²) of it is land and 0.1 square miles (0.3 km²) of it (1.78%) is water.
There were 5,378 households out of which 31.1% had children under the age of 18 living with them, 49.8% were married couples living together, 12.7% had a female householder with no husband present, and 33.4% were non-families. 29.0% of all households were made up of individuals and 13.4% had someone living alone who was 65 years of age or older. The average household size was 2.40 and the average family size was 2.93.
In the city the population was spread out with 26.7% under the age of 18, 8.6% from 18 to 24, 26.7% from 25 to 44, 22.0% from 45 to 64, and 16.1% who were 65 years of age or older. The median age was 36 years. For every 100 females there were 94.8 males. For every 100 females age 18 and over, there were 85.8 males.
The median income for a household in the city was $34,572, and the median income for a family was $41,943. Males had a median income of $32,342 versus $26,115 for females. The per capita income for the city was $17,220. About 11.1% of families and 13.3% of the population were below the poverty line, including 21.4% of those under age 18 and 6.5% of those age 65 or over.
Circleville hosts the Circleville Pumpkin Show every October, which draws over 400,000 visitors each year. Some of the more famous attractions are the baking of the largest pumpkin pie at Lindsey's Bakery, crowning of Miss Pumpkin Show, and the pumpkin weighing contest. Pumpkin Show Facts The Pumpkin Show is known as "The Greatest Free Show on Earth."