Grundy County, Illinois Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates · 26th-largest in Illinois
The population of Grundy County, Illinois is 52,920 as of the 2023 American Community Survey, making it the 26th-largest county in Illinois. The median household income is $93,060, the median home value is $259,200, and the median age is 38.6.
The population of Grundy County has grown 7.3% since 2010 (50,155 → 53,835), a +0.51% annualized rate.
52,920
Population
+0.51%
Annual growth
127
People / sq mi
$93,060
Median Income
$259,200
Median Home Value
Grundy County covers 418 sq mi of land at 126.6 people per square mile.
About Grundy County, IL
Grundy County is a county in Illinois with a population of 52,920. It ranks #26 among counties in Illinois by population. The median age is 38.6, in line with the national median. The population is 50.3% male and 49.7% female.
The median household income in Grundy County is $93,060, above the US median of $74,580. 4.7% of residents live below the federal poverty level. Home values sit at a median of $259,200, with monthly rent averaging $1,137. The homeownership rate of 75.8% is higher than the national rate of 64.8%.
Educational attainment in Grundy County reflects 24.2% of adults 25 and older holding a bachelor's degree or higher, below the national average of 34.3%. Roughly 9.7% of workers primarily work from home, below the national work-from-home rate of 14.2%. The average commute is 27.6 minutes each way.
Grundy County Population History (2010-2024)
The county of Grundy County had a population of 50,155 in 2010 and 53,835 in 2024, a 7.3% growth over 14 years. The peak was 53,835 in 2024. Average annual growth rate: 0.51%.
53,835
Population (2024)
50,155
Population (2010)
53,835
Peak (2024)
0.51%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 50,155 |
| 2011 | 50,103 |
| 2012 | 50,161 |
| 2013 | 50,183 |
| 2014 | 50,281 |
| 2015 | 50,358 |
| 2016 | 50,325 |
| 2017 | 50,627 |
| 2018 | 51,012 |
| 2019 | 51,031 |
| 2020 | 52,535 |
| 2021 | 52,984 |
| 2022 | 53,153 |
| 2023 | 53,587 |
| 2024 | 53,835 |
Race & Ethnicity
| White | 88.4% |
| Black or African American | 2.1% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 0.7% |
| Two or More Races | 0.0% |
Age & Sex
38.6
Median Age
49.7%
Female
50.3%
Male
14.6%
Age 65+
Age Distribution
Children (under 15): 20.1% · Seniors (65+): 14.6%
Income & Poverty
| Median household income | $93,060+$11,358 vs state |
| Mean household income | $111,929 |
| Per-capita income | $43,744 |
| Poverty rate | 4.7%-3.5% vs state |
| Unemployment rate | 3.1% |
| Employment-to-population | 65.1% |
Top Industries by Employment
The largest employment sector in Grundy County is professional & business services, accounting for 21.0% of workers.
How residents commute
0.6%
Drive alone
0.8%
Carpool
83.8%
Public transit
9.7%
Work from home
27.6 min
Avg commute
Housing
$259,200+$8,700 vs state
Median home value
$1,137
Median rent
75.8%
Homeownership rate
21,324
Total housing units
96.2%
Occupied
3.8%
Vacant
24.2%
Renter-occupied
Social & access
96.3%
With health insurance
95.1%
With broadband internet
12.2%
Foreign-born
7.9%
Veterans (18+)
9.7%
With a disability
92.3%
Speak language other than English at home
Education
94.2%
High School+
24.2%
Bachelor's+
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County rankings
Frequently Asked Questions
Grundy County, Illinois has a population of 52,920 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 26th-largest county in Illinois. Population density is 127 people per square mile.
The population of Grundy County has grown 7.3% since 2010 (50,155 → 53,835), a +0.51% annualized rate.
The median household income in Grundy County, Illinois is $93,060, with mean (average) household income of $111,929 and per-capita income of $43,744. 4.7% of residents live below the federal poverty level.
In Grundy County, the largest racial and ethnic groups are White (88.4%), Black or African American (2.1%), Hispanic or Latino (0.7%). Figures are from the US Census Bureau's 2023 ACS 5-year estimates and reflect self-reported responses.
The median age in Grundy County, Illinois is 38.6 years. Residents are 49.7% female and 50.3% male.
The median home value in Grundy County is $259,200 and median monthly rent is $1,137. 75.8% of occupied housing units are owner-occupied. The county has 21,324 total housing units, 3.8% of which are vacant.
The largest employment sector in Grundy County, Illinois is professional, scientific, and management services, employing 21.0% of workers. The unemployment rate is 3.1%.
Chicago is among the largest cities associated with Grundy 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.