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.

In the late 1830s, for various reasons, residents requested authorisation from the state legislature to change Circleville's layout to a standard grid format.

All traces of the Hopewell earthwork were destroyed, although hundreds of other monuments of its kind still remain in the Ohio Valley.

By the mid-18th century, the Lenape (Delaware Indians) were pushed west from Pennsylvania by European settlers flowing into the colony.

[8]: 213–4 Circleville was founded by European-American settlers in 1810, as people relocated westward after the American Revolutionary War.

On February 19 of that year, the assembly appointed David Bradford, George Jackson, and John Pollock to choose the location for the county seat.

A history of the county published in 1880 suggests that the men thought the site location would spur the preservation and maintenance of the Hopewell mounds.

The group was subsequently assigned appointed director Daniel Dreisbach to oversee them on July 25.

Some believed the design was kept only due to "childish sentimentalism", while others complained that the lots were irregular and inconvenient, and that a circular plan wasted space that could otherwise be used to generate revenue.

People from the countryside would hitch their horses around the courthouse, which would draw hogs and domestic animals to the area and surrounding city.

In March 1838, after no activity, the assembly authorized alterations to any quadrant given consent from property owners in the quarter.

Due to these changes, no traces of the original earthworks remain aside from a section of elevated ground at the corner of Pickaway and Franklin streets.

[9]: 34–5 A history of the county makes note that the citizens of Circleville regret the rare circular layout of the town was ever changed.

[9]: 36 During April 1967, Bingman's Drug Store and several neighboring buildings on West Main Street in downtown Circleville were destroyed.

The tornado touched down on the north side of town, dealing considerable damage to a barber's shop and a masonry building.

[16] Damage to nearby buildings occurred as the tornado moved east across the north-central part of town.

The tornado moved into a residential area in the Northwood Park neighborhood, destroying several homes and damaging trees and vehicles.

Starting in 1977,[17][18] residents began receiving mysterious letters from an unknown source identified only as "Writer".

Gillispie and her husband Ronald had previously received letters from the Writer accusing her of engaging in an extramarital affair with school superintendent Gordon Massie.

While the Gillispies' brother-in-law Paul Freshour was sentenced to 10 years in prison for the boobytrap incident in 1984, letters continued to circulate during his imprisonment.

Opened in the 1950s, it produces Mylar and Tedlar plastic films, the latter used extensively in the production of photovoltaic modules.

[32] The PPG Industries Circleville plant is the company's center for polymer resin production, primarily for automotive applications.