O'Fallon Flag

O'Fallon

County Seat:
No
Area (mi²):
15.791
State:
Illinois

O'Fallon is a city located in St. Clair County, Illinois. O'Fallon has a 2025 population of 31,742. O'Fallon is currently declining at a rate of -0.35% annually and its population has decreased by -1.75% since the most recent census, which recorded a population of 32,307 in 2020.

The average household income in O'Fallon is $131,945 with a poverty rate of 4.39%.The median age in O'Fallon is 36.9 years: 35.1 years for males, and 38.2 years for females.

31.7K
Total Population
2,010
Density (mi²)
-113 -0.35%
Growth

O'Fallon Population

O'Fallon Population

Data after 2023 is projected based on recent change

Demographics

The racial composition of O'Fallon includes 72.62% White, 13.61% Black or African American, and smaller percentages for Asian, other race, Native American and multiracial populations.

Population by Race

Race
Population
Percentage (of total)
White23,34072.62%
Black or African American4,37513.61%
Two or more races2,9909.3%
Asian9282.89%
Other race4831.5%
Native American230.07%

O'Fallon Marital Status

OverallMalesFemales0%10%20%30%40%50%60%70%80%90%100%

Married

Widowed

Divorced

Separated

Never Married

Economics and Income Statistics

O'Fallon's average per capita income is $64,936. Household income levels show a median of $102,793. The poverty rate stands at 4.39%.

Families: A family includes the owner or renter of the home along with everyone related to them - whether through birth, marriage, or adoption. This includes relatives like spouses, children, parents, siblings, grandparents, and any other family members.
Households: A household includes all the people who occupy a housing unit (such as a house or apartment) as their usual place of residence.
Non Families: A nonfamily household is either someone living alone or when the owner/renter lives with people they aren't related to, like roommates.
Name
Median
Mean
Married Families$146,065-
Families$126,776$155,518
Households$102,793$131,945
Non Families$50,481$62,451

$64,936

Average Income

$102,793

Median Household Income

4.39%

Poverty Rate

Nearby Cities

Sources

  1. US Census State Population Estimates - Most recent state estimates from the Census Bureau's Population Estimates Program
  2. US Census County Population Estimates - Most recent county estimates from the Census Bureau's Population Estimates Program
  3. American Community Survey (2009 - 2013)
  4. Census QuickFacts
  5. Historical Populations of States and Counties (1790 - 1990)