Jefferson County's estimated 2026 population is 36,182 with a growth rate of 0.1% in the past year according to the most recent United States census data. Jefferson County is the 38th largest county in Illinois. The 2010 population was 38,757 and has seen a growth of -6.64% since that time.
Data after 2023 is projected based on recent change
Overall: 41.2 years
Female: 43.5 years
Male: 39.2 years
There are 28,410 adults, (7,298 of whom are seniors) in Jefferson County.
Female: 17,679 (48.4%)
Male: 18,871 (51.6%)
The racial composition of Jefferson County includes 83.96% White, 6.22% Black or African American, and smaller percentages for Asian, other race, Native American and multiracial populations.
Race | Population | Percentage (of total) |
|---|---|---|
| White | 30,687 | 83.96% |
| Two or more races | 2,776 | 7.6% |
| Black or African American | 2,272 | 6.22% |
| Asian | 376 | 1.03% |
| Other race | 317 | 0.87% |
| Native American | 122 | 0.33% |
Jefferson County's average per capita income is $43,701. Household income levels show a median of $63,118. The poverty rate stands at 13.53%.
Name | Median | Mean |
|---|---|---|
| Married Families | $94,387 | $111,261 |
| Families | $78,998 | $96,235 |
| Households | $63,118 | $80,324 |
| Non Families | $37,721 | $48,369 |
Average Income
Median Household Income
Poverty Rate