Ford County, Illinois in the context of Champaign-Urbana

There are 102 counties in Illinois. The most populous of these is Cook County, the second-most populous county in the United States and the home of Chicago, while the least populous is Hardin County. The largest by land area is McLean County, while the smallest is Putnam County. Illinois's FIPS state code is 17 and its postal abbreviation is IL.

What is now Illinois was claimed as part of Illinois County, Virginia, between 1778 and 1782. Modern-day county formation dates to 1790 when the area was part of the Northwest Territory; two counties — St. Clair and Knox — were created at that time. Knox would later become a county in Indiana and is unrelated to the current Knox County in Illinois, while St. Clair would become the oldest county in Illinois. Successive territorial governments created 15 counties by the time Illinois achieved statehood in 1818. The last county created in the state, Ford County, was created by the Illinois government in 1859.

The Champaign–Urbana metropolitan area, also known as Champaign–Urbana and Urbana–Champaign as well as Chambana (colloquially), is a metropolitan area in east-central Illinois. As defined by the Office of Management and Budget (OMB), the metropolitan area has a population of 235,608 as of the 2023 U.S. Census Bureau estimate, which ranks it as the 201st largest metropolitan statistical area in the U.S. The area is anchored by the principal cities of Champaign and Urbana, and is home to the University of Illinois Urbana-Champaign, the flagship campus of the University of Illinois system.

As of July 2023, the OMB defines the metropolitan area (officially designated the Champaign–Urbana, IL MSA) to consist of Champaign County, Piatt County, and Ford County. From 2018 to 2023, Ford County was not considered a part of the metropolitan area.The MSA is part of the larger Champaign–Urbana–Danville Combined Statistical Area, which also includes the Danville micropolitan area, and has a population of 307,260 as of the 2023 estimate.