Lee County, Illinois Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 42nd-largest in Illinois
The population of Lee County, Illinois is 34,058 as of the 2023 American Community Survey, making it the 42nd-largest county in Illinois. The median household income is $68,459, the median home value is $155,100, and the median age is 43.0.
The population of Lee County has declined 6.8% since 2010 (35,978 → 33,544), a -0.50% annualized rate.
34,058
Population
-0.50%
Annual growth
47
People / sq mi
$68,459
Median Income
$155,100
Median Home Value
Lee County covers 725 sq mi of land at 47.0 people per square mile.
About Lee County, IL
Lee County is a county in Illinois with a population of 34,058. It ranks #42 among counties in Illinois by population. The median age is 43.0, older than the national median. The population is 52.8% male and 47.2% female.
The median household income in Lee County is $68,459, below the US median of $74,580. 7.3% of residents live below the federal poverty level. Home values sit at a median of $155,100, with monthly rent averaging $853. The homeownership rate of 73.3% is higher than the national rate of 64.8%.
Educational attainment in Lee County reflects 19.4% of adults 25 and older holding a bachelor's degree or higher, below the national average of 34.3%. Roughly 5.3% of workers primarily work from home, below the national work-from-home rate of 14.2%. The average commute is 24.3 minutes each way.
Lee County Population History (2010-2024)
The county of Lee County had a population of 35,978 in 2010 and 33,544 in 2024, a -6.8% growth over 14 years. The peak was 35,978 in 2010. Average annual growth rate: -0.50%.
33,544
Population (2024)
35,978
Population (2010)
35,978
Peak (2010)
-0.50%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 35,978 |
| 2011 | 35,611 |
| 2012 | 35,218 |
| 2013 | 35,123 |
| 2014 | 34,912 |
| 2015 | 34,521 |
| 2016 | 34,499 |
| 2017 | 34,533 |
| 2018 | 34,281 |
| 2019 | 34,061 |
| 2020 | 34,063 |
| 2021 | 34,202 |
| 2022 | 33,928 |
| 2023 | 33,606 |
| 2024 | 33,544 |
Race & Ethnicity
| White | 86.8% |
| Black or African American | 5.4% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 1.0% |
| Two or More Races | 0.0% |
Age & Sex
43.0
Median Age
47.2%
Female
52.8%
Male
20.8%
Age 65+
Age Distribution
Children (under 15): 16.3% · Seniors (65+): 20.8%
Income & Poverty
| Median household income | $68,459$-13,243 vs state |
| Mean household income | $88,472 |
| Per-capita income | $35,065 |
| Poverty rate | 7.3%-0.9% vs state |
| Unemployment rate | 2.0% |
| Employment-to-population | 54.3% |
Top Industries by Employment
The largest employment sector in Lee County is professional & business services, accounting for 24.1% of workers.
How residents commute
0.8%
Drive alone
1.2%
Carpool
83.6%
Public transit
5.3%
Work from home
24.3 min
Avg commute
Housing
$155,100$-95,400 vs state
Median home value
$853
Median rent
73.3%
Homeownership rate
14,993
Total housing units
89.3%
Occupied
10.7%
Vacant
26.7%
Renter-occupied
Social & access
96.4%
With health insurance
91.3%
With broadband internet
14.9%
Foreign-born
6.9%
Veterans (18+)
16.3%
With a disability
95.7%
Speak language other than English at home
Education
90.5%
High School+
19.4%
Bachelor's+
Largest cities in Illinois
Other counties in Illinois
Part of Illinois
Metro areas in Illinois
County rankings
Frequently Asked Questions
Lee County, Illinois has a population of 34,058 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 42nd-largest county in Illinois. Population density is 47 people per square mile.
The population of Lee County has declined 6.8% since 2010 (35,978 → 33,544), a -0.50% annualized rate.
The median household income in Lee County, Illinois is $68,459, with mean (average) household income of $88,472 and per-capita income of $35,065. 7.3% of residents live below the federal poverty level.
In Lee County, the largest racial and ethnic groups are White (86.8%), Black or African American (5.4%), Hispanic or Latino (1.0%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in Lee County, Illinois is 43.0 years. Residents are 47.2% female and 52.8% male.
The median home value in Lee County is $155,100 and median monthly rent is $853. 73.3% of occupied housing units are owner-occupied. The county has 14,993 total housing units, 10.7% of which are vacant.
The largest employment sector in Lee County, Illinois is professional, scientific, and management services, employing 24.1% of workers. The unemployment rate is 2.0%.
Chicago is among the largest cities associated with Lee County, Illinois, with a population of 2,707,648.
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Statewide data for Illinois
Population, race, income, age, and trends across Illinois
Data from the American Community Survey (ACS) 5-Year estimates.
Source: U.S. Census Bureau ACS, 2026.