How many people live in Lake County, IL?
Updated Apr. 6, 2026Refreshed annually
In 2024, there were about 718,600 people living in Lake County, IL. That makes Lake County the third-most populous county in Illinois. It is home to 5.6% of people living in the state.
719K
population of Lake County, IL (2024)
5.6%
County share of the Illinois population (2024)
About 718,600 people lived in Lake County, IL in 2024.
Population estimates, 2000–2024
What are Lake County, IL’s age demographics?
About 121,600 Lake County, IL residents are aged 65 and older in 2024. That represents 16.9% of its population. For comparison, the age group represents 17.9% of Illinois’ population and 18% in the US overall.
Another 162,200 Lake County, IL residents, or 22.6% 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 lower share of Lake County, IL's population is aged 25–44 than the US as a whole.
Population estimates by age group, (2024)
What are Lake County, IL’s racial and ethnic demographics?
Hispanic residents make up 25.7% of the Lake County, IL population, higher than the national share of 20%. Lake County, IL also has a larger share of people identifying as non-Hispanic Asian (9.7%) than the US overall (6.5%).
In contrast, Lake County’s non-Hispanic Black or African American population accounts for 6.8%, below the 12.6% nationwide, and the non-Hispanic white population makes up 55.8% of the county, compared with 57.5% 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.
Lake County, IL has a higher share of a Hispanic population than Illinois as a whole.
Population estimates by race and ethnicity, (2024)
The largest city or town in Lake County, IL is Waukegan with about 75,400 residents in 2024.
Cities and towns in Lake County, IL ranked by population
Population (2024), includes only portions within county
| City or town | Population | |
|---|---|---|
| 1. | Waukegan (pt.) | 75,426 |
| 2. | Gurnee (pt.) | 30,525 |
| 3. | Buffalo Grove (pt.) | 29,563 |
| 4. | Highland Park (pt.) | 26,728 |
| 5. | Zion | 24,583 |
| 6. | North Chicago (pt.) | 20,942 |
| 7. | Libertyville (pt.) | 20,638 |
| 8. | Round Lake Beach (pt.) | 20,455 |
| 9. | Lake Zurich | 19,960 |
| 10. | Grayslake (pt.) | 19,626 |
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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.
