How many people live in Cook County, IL?
Updated Apr. 6, 2026Refreshed annually
In 2024, there were about 5.18 million people living in Cook County, IL. That makes Cook County the second-most populous county in the US. It is also the largest in Illinois, accounting for 40.7% of the state’s population.
5.18M
population of Cook County, IL (2024)
40.7%
County share of the Illinois population (2024)
About 5.18 million people lived in Cook County, IL in 2024.
Population estimates, 2000–2024
What are Cook County, IL’s age demographics?
About 870,400 Cook County, IL residents are aged 65 and older in 2024. That represents 16.8% of its population. For comparison, the age group represents 17.9% of Illinois' population and 18% in the US overall.
Another 1.05 million Cook County, IL residents, or 20.3% of the population, were children under 18. For comparison, the age group represents 21.2% of Illinois’s population and 21.6% in the US overall.
A higher share of Cook County, IL's population is aged 25–44 than the US as a whole.
Population estimates by age group, (2024)
What are Cook County, IL’s racial and ethnic demographics?
Hispanic residents make up 27.3% of the Cook County, IL population, higher than the national share of 20%. Cook County, IL also has a larger share of people identifying as non-Hispanic Black or African American (22%) than the US overall (12.6%).
In contrast, Cook County’s non-Hispanic white population accounts for 40.2%, below the 57.5% nationwide, and the non-Hispanic two or more races population makes up 1.8% of the county, compared with 2.5% nationally.
Racial and ethnic make up differ based on location. These figures reflect how people identified their race alone (not in combination with other races), and separate out Hispanic or Latino ethnicity, following Census reporting standards.
Cook County, IL has a higher share of a non-Hispanic Black or African American population than Illinois as a whole.
Population estimates by race and ethnicity, (2024)
The largest city or town in Cook County, IL is Chicago with about 2.72 million residents in 2024.
Cities and towns in Cook County, IL ranked by population
Population (2024), includes only portions within county
| City or town | Population | |
|---|---|---|
| 1. | Chicago (pt.) | 2,721,308 |
| 2. | Cicero | 82,090 |
| 3. | Evanston | 76,006 |
| 4. | Schaumburg (pt.) | 69,846 |
| 5. | Palatine (pt.) | 65,894 |
| 6. | Skokie | 65,850 |
| 7. | Arlington Heights (pt.) | 61,134 |
| 8. | Oak Lawn | 56,531 |
| 9. | Orland Park (pt.) | 56,134 |
| 10. | Berwyn | 55,152 |
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Methodology
USAFacts standardizes data, in areas such as time and demographics, to make it easier to understand and compare.
The analysis was generated with the help of AI and reviewed by USAFacts for accuracy.
Page sources
USAFacts endeavors to share the most up-to-date information available. We sourced the data on this page directly from government agencies; however, the intervals at which agencies publish updated data vary.
