City in St. Clair County, Illinois
O'Fallon
District lines run through O'Fallon, so who represents you here depends on your street. Search your address to see yours.
Who lives in O'Fallon
Census survey estimates for 2020 to 2024, rounded.
People
- Population
- 32,300
- Median age
- 37.8 years
- Under 18
- 26%
- 65 and over
- 17%
- Veterans, of adults
- 20%
- Speak another language at home
- 5%
Race and ethnicity
- Hispanic or Latino, of any race
- 5%
- White, not Hispanic
- 69%
- Black, not Hispanic
- 17%
- Asian, not Hispanic
- 3%
Income and housing
- Median household income
- $106,000
- Below the poverty line
- 6%
- Bachelor's or higher, adults 25+
- 52%
- Owner-occupied homes
- 70%
- Median home value
- $296,000
2024 vote for president
Not counted for O'Fallon on its own: its precincts follow township lines, not the town’s. See the figure for St. Clair County.
Represent all of O'Fallon
Represent part of O'Fallon
Each represents the part of O'Fallon inside their district. Under each is how many people lived in that part at the 2020 Census, of 32,289 in all.
Mike BostU.S. Representative, District 12, Republican22,337 people in this part
Nikki BudzinskiU.S. Representative, District 13, Democratic9,952 people in this part- JPJason PlummerState Senator, District 55, Republican3,167 people in this part
- EHErica HarrissState Senator, District 56, Republican6,958 people in this part
- CBChristopher BeltState Senator, District 57, Democratic22,164 people in this part
- CMCharlie MeierState Representative, District 109, Republican3,167 people in this part
- KSKatie StuartState Representative, District 112, Democratic6,958 people in this part
- JHJay HoffmanState Representative, District 113, Democratic6,794 people in this part
- KSKevin SchmidtState Representative, District 114, Republican15,370 people in this part
O'Fallon's districts (9)
U.S. House (2)
- U.S. House District 12
Held by Mike Bost, Republican
Part of O'Fallon: 22,337 people in 2020
- U.S. House District 13
Held by Nikki Budzinski, Democratic
Part of O'Fallon: 9,952 people in 2020
Illinois Senate (3)
- Illinois Senate District 55
Held by Jason Plummer, Republican
Part of O'Fallon: 3,167 people in 2020
- Illinois Senate District 56
Held by Erica Harriss, Republican
Part of O'Fallon: 6,958 people in 2020
- Illinois Senate District 57
Held by Christopher Belt, Democratic
Part of O'Fallon: 22,164 people in 2020
Illinois House (4)
- Illinois House District 109
Held by Charlie Meier, Republican
Part of O'Fallon: 3,167 people in 2020
- Illinois House District 112
Held by Katie Stuart, Democratic
Part of O'Fallon: 6,958 people in 2020
- Illinois House District 113
Held by Jay Hoffman, Democratic
Part of O'Fallon: 6,794 people in 2020
- Illinois House District 114
Held by Kevin Schmidt, Republican
Part of O'Fallon: 15,370 people in 2020
Source: U.S. Census Bureau, American Community Survey 5-year estimates, 2020–2024; towns and counties from the 2020 Census, 119th Congressional District and 2024 state legislative district tabulation. Figures rounded by us. Retrieved 2026-10-19. This product uses the Census Bureau Data API but is not endorsed or certified by the Census Bureau.