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 distinguished by its share of foreign-born residents, 14.9% of the population. Lee County is a county in Illinois with a population of 34,058. It ranks #42 among counties in Illinois by population.
The typical household here earns about $68,459, below the US median of $78,538. About 7.3% of residents live below the federal poverty level, below the national 12.4%. Homes carry a median value of $155,100, with typical rent around $853.
Degree attainment is mid-range for US counties: 19.4% of adults hold a four-year degree, below the national 35.0%. Most workers commute: only 5.3% work from home, below the national 14.0%, and the average commute runs about 24 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.