Cook County Flag

Cook County

State:
Illinois
County Seat:
Chicago

Cook County's estimated 2025 population is 5,038,084 with a growth rate of -0.48% in the past year according to the most recent United States census data. Cook County is the 1st largest county in Illinois. The 2010 population was 5,198,977 and has seen a growth of -3.09% since that time.

5,038,084
Total Population
5,331
Population Density (mi²)
1
Population Rank (State)
-24.5K -0.48%
Annual Population Growth

Cook County Population

Demographics

Economics and Income Statistics