Where is Cook County?

3 Cook Counties in 3 states · 5.2 million people (2025)

There are 3 counties named Cook County in the United States, in Georgia, Illinois and Minnesota. The most populous is Cook County, Illinois (county seat: Chicago), with 5,194,625 people in 2025.

Map of the United States showing where all 3 Cook Counties are, labeled by state
Every Cook County in the United States (red), labeled with its state. Boundaries: U.S. Census Bureau, 2025. Free to use with attribution (CC BY 4.0).

All 3 Cook Counties

Sorted by state. Each link opens the county's map.

StateCounty seatPopulation 2025Land area (sq mi)EstablishedNamed after
Cook County, GeorgiaAdel18,2322291918Philip Cook
Cook County, IllinoisChicago5,194,6259451831Daniel Pope Cook
Cook County, MinnesotaGrand Marais5,5221,4531874–

Questions about Cook Counties

How many Cook Counties are there?

There are 3 Cook Counties in the United States, in Georgia, Illinois and Minnesota.

Which Cook County is the largest?

By population, Cook County, Illinois (5,194,625 people in 2025). By land area, Cook County, Minnesota (1,453 sq mi).

Which Cook County is the oldest?

Cook County, Illinois, established in 1831. The newest is Cook County, Georgia (1918).

How do I find out which Cook County an address is in?

Open the county map of the state: it has a search box for cities, towns and ZIP codes. On a phone, the "what county am I in" tool on our sister site uses your location.

What county am I in? →

Other common county names