Illinois Counties
Illinois, state of the United States of America. There are 102 county in Illinois. You can find the list of these counties and detailed information from the links below.
Cook County
Cook County, population 5,108,284
DuPage County
DuPage County, population 917,481
Lake County
Lake County, population 693,593
With 102 counties, Illinois contains a mix of bustling metropolises, quaint farm towns, and everything in between. Here are some notable counties:
Cook County - Home to Chicago, Cook County is the most populous in Illinois with over 5 million residents. Chicago dominates business, culture, and tourism in the county.
DuPage County - Bordering Cook County, DuPage County contains affluent, well-educated suburbs of Chicago like Naperville and Oak Brook. With over 920,000 residents, it is Illinois' second most populous county.
Lake County - Located along Lake Michigan north of Chicago, Lake County is another suburban county with deep ties to Chicago. Industries like biotech and manufacturing thrive in its cities.
Sangamon County - Springfield, the state capital, anchors Sangamon County in central Illinois. Abraham Lincoln history shapes Sangamon's character and tourism.
McLean County - With over 170,000 residents, McLean County is considered one of Illinois' metropolitan areas because of its size and industries. Bloomington and Normal are McLean's largest cities.
Adams County - Along Illinois' western border, Adams County maintains a rustic character defined by the Mississippi River. Quincy is its largest city. Agriculture drives the economy.
Hardin County - Sparsely populated Hardin County represents small-town Illinois. Under 5,000 residents spread across this scenic lower Illinois county along the Ohio River.
The diversity of Illinois' counties reflects the state's blend of major midwestern cities, small farming communities, suburbs, and river towns, each contributing unique local flavor.
