How many people live in Kendall County, IL?
Updated Apr. 6, 2026Refreshed annually
In 2024, there were about 143,200 people living in Kendall County, IL. That makes Kendall County the 14th-most populous county in Illinois. It is home to 1.1% of people living in the state.
143K
population of Kendall County, IL (2024)
1.1%
County share of the Illinois population (2024)
About 143,200 people lived in Kendall County, IL in 2024.
Population estimates, 2000–2024
What are Kendall County, IL’s age demographics?
About 16,900 Kendall County, IL residents are aged 65 and older in 2024. That represents 11.8% of its population. For comparison, the age group represents 17.9% of Illinois' population and 18% in the US overall.
Another 37,400 Kendall County residents, or 26.1% 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 Kendall County, IL's population is aged 65 or older than the US as a whole.
Population estimates by age group, (2024)
What are Kendall County, IL’s racial and ethnic demographics?
Non-Hispanic white residents make up 60.5% of the Kendall County, IL population, higher than the national share of 57.5%. Kendall County, IL also has a larger share of people identifying as Hispanic (23.6%) than the US overall (20%).
In contrast, Kendall County’s non-Hispanic Black or African American population accounts for 9.2%, below the 12.6% nationwide, and the non-Hispanic Asian population makes up 4.6% of the county, compared with 6.5% 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.
Kendall 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 Kendall County, IL is Oswego with about 35,100 residents in 2024.
Cities and towns in Kendall County, IL ranked by population
Population (2024), includes only portions within county
| City or town | Population | |
|---|---|---|
| 1. | Oswego (pt.) | 35,059 |
| 2. | Yorkville (pt.) | 18,259 |
| 3. | Plano | 12,677 |
| 4. | Montgomery (pt.) | 10,424 |
| 5. | Joliet (pt.) | 9,545 |
| 6. | Yorkville (pt.) | 7,713 |
| 7. | Aurora (pt.) | 6,431 |
| 8. | Joliet (pt.) | 4,916 |
| 9. | Oswego (pt.) | 3,719 |
| 10. | Plainfield (pt.) | 3,047 |
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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.
