Jefferson County, Illinois

Jefferson County, Illinois, had an estimated population of 36,147 in 2025 across 1,479 km². The figures below come from the US Census Bureau's population estimates and the American Community Survey, each shown with its own vintage and its rank among Illinois's counties and nationally.

Population: 36,147; 2025 estimate
Area: 1,479 km²
Density: 24; per km²
Median income: $63,118; household, ACS 2024
Median age: 41.2; years, ACS 2024

How Illinois's counties spread

Amenities & Infrastructure

Indicator	Value	In Illinois	In the US
Households with Broadband2024	85.7%	72 / 102	1,861 / 3,144
Median Gross Rent2024	$885	31 / 102	1,515 / 3,137
Median Home Value2024	$126,000	63 / 102	2,535 / 3,139
Owner-Occupied Homes2024	71.7%	82 / 102	2,018 / 3,144
Vacant Homes2024	10.9%	49 / 102	2,050 / 3,144

Demography

Indicator	Value	In Illinois	In the US
Aged 65 and Over2024	20.0%	61 / 102	1,564 / 3,144
American Indian & Alaska Native2024	0.3%	5 / 102	922 / 3,144
Asian, non-Hispanic2024	1.0%	24 / 102	1,011 / 3,144
Average Household Size2024people	2.4	39 / 102	1,911 / 3,144
Black, non-Hispanic2024	5.8%	29 / 102	1,016 / 3,144
Foreign-Born2024	1.9%	45 / 102	2,033 / 3,144
Hispanic or Latino2024	2.8%	59 / 102	2,297 / 3,144
Median Age2024years	41.2	67 / 102	1,652 / 3,144
Sex Ratio2024per 1,000 males	937	83 / 102	2,595 / 3,144
Speak a Language Other Than English2024	3.6%	46 / 102	2,116 / 3,144
Under 182024	22.3%	31 / 102	1,356 / 3,144
Veterans2024	7.7%	43 / 102	1,231 / 3,144
White, non-Hispanic2024	83.6%	68 / 102	1,374 / 3,144

Economy

Indicator	Value	In Illinois	In the US
Below Poverty Line2024	13.5%	41 / 102	1,491 / 3,144
Households on SNAP2024	17.1%	22 / 102	655 / 3,144
Income Inequality2024index	0.433	51 / 102	2,026 / 3,144
Median Household Income2024	$63,118	67 / 102	1,783 / 3,143
Per Capita Income2024	$33,038	75 / 102	1,920 / 3,144
Unemployment Rate2024	5.8%	20 / 102	715 / 3,144

Education

Indicator	Value	In Illinois	In the US
Bachelor's Degree or Higher2024	18.2%	81 / 102	2,245 / 3,144
High School or Higher2024	92.3%	42 / 102	983 / 3,144

Health Coverage

Indicator	Value	In Illinois	In the US
No Health Insurance2024	7.2%	15 / 102	1,744 / 3,144
With a Disability2024	18.3%	23 / 102	933 / 3,144

Population & Density

Indicator	Value	In Illinois	In the US
Population2025	36,147	38 / 102	1,295 / 3,144
Population Density2025/km²	24	38 / 102	1,267 / 3,144

Work & Commute

Indicator	Value	In Illinois	In the US
Commute by Public Transit2024	0.3%	45 / 102	1,112 / 3,144
Households with No Vehicle2024	6.3%	45 / 102	1,091 / 3,144
Mean Commute Time2024minutes	19.6	89 / 102	2,527 / 3,143
Work from Home2024	5.4%	80 / 102	2,525 / 3,144

Other counties of Illinois

Compare Jefferson County against every other county on a map, add layers and run a scatter — open the atlas. Sources and vintages for every figure on this page are listed under datasets, or browse all 3,144 counties.