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 2026 population of 32,047. O'Fallon is currently declining at a rate of -0.19% annually and its population has decreased by -1.13% since the most recent census, which recorded a population of 32,413 in 2020.

The median household income in O'Fallon is $105,982 with a poverty rate of 6.2%. The median age in O'Fallon is 37.8 years: 36 years for males, and 39.2 years for females. For every 100 females there are 98.1 males.

32K
Total Population
2,029
Density (mi²)
-61 -0.19%
Growth

O'Fallon Population

O'Fallon Population

Data after 2023 is projected based on recent change

Year ↓
Population
Growth
Annual Change
202632,047-61-0.19%
202532,108-61-0.19%
202432,169-17-0.05%
202332,186-61-0.19%
202232,247-142-0.44%
202132,389-43-0.13%
202032,4132,7929.43%
201929,621190.06%
201829,6022380.81%
201729,3641650.57%
201629,199750.26%
201529,124-27-0.09%
201429,151-73-0.25%
201329,224-104-0.35%
201229,328-95-0.32%
201129,4236172.14%
201028,8065251.86%
200021,9105,83736.32%
199016,0733,90032.04%
198012,1734,90567.49%
19707,2683,25080.89%
19604,01899632.96%
19503,02200%

Median Age

Overall: 37.8 years
Female: 39.2 years
Male: 36 years

O'Fallon Adults

There are 23,825 adults, (5,382 of whom are seniors) in O'Fallon.

Sex Ratio

Female: 16,284 (50.5%)
Male: 15,978 (49.5%)

Demographics

The racial composition of O'Fallon includes 70.08% White, 16.95% Black or African American, and smaller percentages for Asian, other race, Native American and multiracial populations.

Population by Race

Race
Population ↓
Percentage (of total)
White22,61070.08%
Black or African American5,46816.95%
Two or more races2,7898.64%
Asian8462.62%
Other race5241.62%
Native American250.08%
Race
Population ↓
Percentage (of total)
Two or more races9082.81%
Other race3791.17%
White2280.71%
Black or African American1330.41%
Asian130.04%
Race
Population ↓
Percentage (of total)
White22,38269.38%
Black or African American5,33516.54%
Two or more races1,8815.83%
Asian8332.58%
Other race1450.45%
Native American250.08%

O'Fallon Marital Status

Economics and Income Statistics

O'Fallon 's average per capita income is $62,313. Household income levels show a median of $105,982. The poverty rate stands at 6.2%.

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$151,434-
Families$129,297$161,583
Households$105,982$136,093
Non Families$52,377$67,949

$62,313

Average Income

$105,982

Median Household Income

6.2%

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)