O'Fallon, Illinois Population 2026
Updated April 2026 · US Census ACS 2023 5-Year Estimates
The population of O'Fallon, Illinois is 32,139 as of the 2023 American Community Survey, making it the 58th-largest city in Illinois. The median household income is $102,793, the median home value is $274,100, and the median age is 36.9.
The population has grown 11.7% since 2010 (28,797 → 32,169).
32,139
Population
2033
People / sq mi
$102,793
Median Income
$274,100
Median Home Value
O'Fallon covers 15.8 sq mi of land at 2033 people per square mile.
About O'Fallon, IL
O'Fallon is a city in Illinois with a population of 32,139. It ranks #58 among cities in Illinois by population. The median age is 36.9, younger than the national median. The population is 49.4% male and 50.6% female.
The median household income in O'Fallon is $102,793, above the US median of $74,580. 3.1% of residents live below the federal poverty level. Home values sit at a median of $274,100, with monthly rent averaging $1,312. The homeownership rate of 70.9% is higher than the national rate of 64.8%.
Educational attainment in O'Fallon reflects 51.3% of adults 25 and older holding a bachelor's degree or higher, above the national average of 34.3%. Roughly 16.7% of workers primarily work from home, similar to the national work-from-home rate of 14.2%. The average commute is 26.1 minutes each way.
O'Fallon city Population History (2010-2024)
The city of O'Fallon city had a population of 28,797 in 2010 and 32,169 in 2024, a 11.7% growth over 14 years. The peak was 32,413 in 2020. Average annual growth rate: 0.82%.
32,169
Population (2024)
28,797
Population (2010)
32,413
Peak (2020)
0.82%
Avg Annual Growth
| Year | Population |
|---|---|
| 2010 | 28,797 |
| 2011 | 29,407 |
| 2012 | 29,311 |
| 2013 | 29,199 |
| 2014 | 29,128 |
| 2015 | 29,098 |
| 2016 | 29,153 |
| 2017 | 29,320 |
| 2018 | 29,557 |
| 2019 | 29,583 |
| 2020 | 32,413 |
| 2021 | 32,389 |
| 2022 | 32,247 |
| 2023 | 32,186 |
| 2024 | 32,169 |
Race & Ethnicity
| White | 72.6% |
| Black or African American | 13.6% |
| Asian | 0.0% |
| Hispanic or Latino (any race) | 2.5% |
| Two or More Races | 0.0% |
Economy & Income
$102,793
Median Household Income
$51,826
Per Capita Income
3.1%
Poverty Rate
2.1%
Unemployment Rate
Housing
$274,100
Median Home Value
$1,312
Median Rent
70.9%
Owner-Occupied
Education
96.9%
High School+
51.3%
Bachelor's+
Commute
0.4%
Drive Alone
75.2%
Public Transit
16.7%
Work From Home
26.1 min
Avg Commute
Community Profile
48.1%
Foreign Born
92.9%
Non-English at Home
19.4%
Veterans
10.5%
With Disability
95.7%
Health Insurance
97.8%
Internet Access
Employment by Industry
| Professional, Scientific & Management | 24.7% |
| Finance, Insurance & Real Estate | 16.0% |
| Public Administration | 10.4% |
| Information | 8.1% |
| Education, Health Care & Social Services | 7.8% |
| Retail Trade | 7.4% |
| Manufacturing | 6.5% |
| Arts, Entertainment & Food Services | 3.4% |
| Construction | 3.4% |
| Transportation & Warehousing | 1.2% |
| Agriculture & Mining | 0.4% |
Largest cities in Illinois
Largest counties in Illinois
Part of Illinois
Metro areas in Illinois
City rankings
Frequently Asked Questions
O'Fallon, Illinois has a population of 32,139 according to the US Census Bureau's 2023 American Community Survey 5-year estimates, making it the 58th-largest city in Illinois.
The median household income in O'Fallon, Illinois is $102,793, with 3.1% of residents living below the federal poverty level.
The median home value in O'Fallon, Illinois is $274,100, with median monthly rent at $1,312 and a homeownership rate of 70.9%.
The median age in O'Fallon, Illinois is 36.9 years. The population is 49.4% male and 50.6% female.
The population has grown 11.7% since 2010 (28,797 → 32,169).
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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.