Frankfort is a village in Will County, Illinois, United States, with a small portion in Cook County. The population was 17,782 at the 2010 census, up from 10,391 in 2000. According to Forbes.com, in 2007 the village ranked as the 36th fastest growing suburb in the United States.
The name "Frankfort" was taken from Frankfort Township as designated by the governing board of Will County. It was commonly known as "Frankfort Station" after the opening of the Joliet & Northern Indiana Railroad through the township in 1855, though the official plat of the community dated March 1855 shows the name as "Frankfort". Property deed abstracts and railroad documents also show that the name was always Frankfort. Local residents incorporated Frankfort as a village in 1879. It also has some reference to the major German city of Frankfurt.
First inhabited by Native Americans, including the Potawatomi and Sac and Fox tribes, Frankfort was used as a conduit between the Des Plaines and St. Joseph rivers. Originally, the area was part of the Virginia Territory before the French signed a treaty with Manitoqua, the Potawatomi chief, for land in the Prestwick area.