Lake County, Illinois Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 3rd-largest in Illinois
The population of Lake County, Illinois is 711,885 as of the 2023 American Community Survey, making it the 3rd-largest county in Illinois. The median household income is $108,917, the median home value is $326,600, and the median age is 38.9.
The population of Lake County has grown 2.0% since 2010 (704,179 → 718,604), a +0.14% annualized rate.
711,885
Population
+0.14%
Annual growth
1605
People / sq mi
$108,917
Median Income
$326,600
Median Home Value
Lake County covers 444 sq mi of land at 1604.5 people per square mile.
About Lake County, IL
Among US counties, Lake County stands out first on household income: a median of $108,917, above the US median of $78,538. With 711,885 residents, Lake County is a county in Illinois. It is the #3-largest of all counties in Illinois nationally.
Earnings sit at the high end: a median household income of $108,917, above the US median of $78,538. Only 5.4% of residents live in poverty, below the national 12.4%. A typical home is worth $326,600, with typical rent around $1,434.
The population is unusually well-credentialed for US counties — 47.0% of adults have a four-year degree, above the national 35.0%. Remote work is widespread — 17.3% of workers stay home, above the national 14.0%, and the average commute runs about 29 minutes each way.
Taken together, the income and housing figures place Lake County firmly in the higher-cost, higher-earning tier of US counties — a profile that tends to track dense job markets and competitive housing.
Lake County Population History (2010-2024)
The county of Lake County had a population of 704,179 in 2010 and 718,604 in 2024, a 2.0% growth over 14 years. The peak was 718,604 in 2024. Average annual growth rate: 0.15%.
718,604
Population (2024)
704,179
Population (2010)
718,604
Peak (2024)
0.15%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 704,179 |
| 2011 | 701,652 |
| 2012 | 702,117 |
| 2013 | 704,259 |
| 2014 | 704,359 |
| 2015 | 704,687 |
| 2016 | 704,401 |
| 2017 | 702,825 |
| 2018 | 700,455 |
| 2019 | 697,134 |
| 2020 | 713,426 |
| 2021 | 712,733 |
| 2022 | 712,143 |
| 2023 | 714,207 |
| 2024 | 718,604 |
Race & Ethnicity
| White | 64.0% |
| Black or African American | 6.6% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 1.9% |
| Two or More Races | 0.0% |
Age & Sex
38.9
Median Age
49.7%
Female
50.3%
Male
15.4%
Age 65+
Age Distribution
Children (under 15): 18.9% · Seniors (65+): 15.4%
Income & Poverty
| Median household income | $108,917+$27,215 vs state |
| Mean household income | $152,447 |
| Per-capita income | $55,756 |
| Poverty rate | 5.4%-2.8% vs state |
| Unemployment rate | 3.4% |
| Employment-to-population | 63.2% |
Top Industries by Employment
The largest employment sector in Lake County is professional & business services, accounting for 20.2% of workers.
How residents commute
2.8%
Drive alone
2.0%
Carpool
68.0%
Public transit
17.3%
Work from home
28.8 min
Avg commute
Housing
$326,600+$76,100 vs state
Median home value
$1,434
Median rent
74.4%
Homeownership rate
270,083
Total housing units
95.0%
Occupied
5.0%
Vacant
25.6%
Renter-occupied
Social & access
93.1%
With health insurance
96.7%
With broadband internet
19.8%
Foreign-born
5.1%
Veterans (18+)
9.9%
With a disability
69.0%
Speak language other than English at home
Education
90.6%
High School+
47.0%
Bachelor's+
Largest cities in Illinois
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County rankings
Common questions about Lake County, IL
Frequently Asked Questions
Lake County, Illinois has a population of 711,885 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 3rd-largest county in Illinois. Population density is 1605 people per square mile.
The population of Lake County has grown 2.0% since 2010 (704,179 → 718,604), a +0.14% annualized rate.
The median household income in Lake County, Illinois is $108,917, with mean (average) household income of $152,447 and per-capita income of $55,756. 5.4% of residents live below the federal poverty level.
In Lake County, the largest racial and ethnic groups are White (64.0%), Black or African American (6.6%), Hispanic or Latino (1.9%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in Lake County, Illinois is 38.9 years. Residents are 49.7% female and 50.3% male.
The median home value in Lake County is $326,600 and median monthly rent is $1,434. 74.4% of occupied housing units are owner-occupied. The county has 270,083 total housing units, 5.0% of which are vacant.
The largest employment sector in Lake County, Illinois is professional, scientific, and management services, employing 20.2% of workers. The unemployment rate is 3.4%.
Chicago is among the largest cities associated with Lake 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.