Grundy County's 2026 population is estimated at 54,331, reflecting a 0.46% growth rate over the past year (World Population Review estimate based on U.S. Census Bureau data). Grundy County is the 25th largest county in Illinois. The 2010 population was 50,155 and has grown 8.33% since 2010.
Data after 2023 is projected based on recent change
Overall: 38.3 years
Female: 39.5 years
Male: 37.1 years
There are 40,280 adults, (8,031 of whom are seniors) in Grundy County.
Female: 26,410 (49.6%)
Male: 26,809 (50.4%)
The racial composition of Grundy County includes 86.31% White, 3.38% other race, and smaller percentages for Black or African American, Asian, Native American and multiracial populations.
| Race | Population ↓ | Percentage (of total) |
|---|---|---|
| White | 45,933 | 86.31% |
| Two or more races | 3,929 | 7.38% |
| Other race | 1,798 | 3.38% |
| Black or African American | 1,220 | 2.29% |
| Asian | 301 | 0.57% |
| Native American | 38 | 0.07% |
Grundy County 's average per capita income is $57,775. Household income levels show a median of $92,235. The poverty rate stands at 5.99%.
| Name | Median ↓ | Mean |
|---|---|---|
| Married Families | $119,060 | - |
| Families | $110,082 | $129,324 |
| Households | $92,235 | $111,828 |
| Non Families | $58,282 | $69,527 |
Average Income
Median Household Income
Poverty Rate
