O'Fallon Population 2026
O'Fallon has a population of 85,040, making it the #420 biggest city in 🇺🇸 United States, located in Missouri. It is about 104× smaller than New York City, the country's biggest city.
Population (city proper)
85,040
Rank in United States
#420
Coordinates
38.81°N, 90.70°W
~165 m elevation · America/Chicago
Distance to capital (Washington)
1,182 km
734 miles, straight line
Other big cities in Missouri
| City | Population | Rank in United States |
|---|---|---|
| Kansas City | 475,378 | #40 |
| St. Louis | 279,695 | #75 |
| Springfield | 170,188 | #157 |
| Columbia | 129,330 | #223 |
| Independence | 117,255 | #249 |
| Lee's Summit | 95,094 | #349 |
| Saint Joseph | 76,780 | #481 |
| Saint Charles | 65,794 | #598 |
Cities near O'Fallon
- Saint Peters52,575 people · ~6 km away
- Wentzville35,603 people · ~13 km away
- Saint Charles65,794 people · ~19 km away
- Chesterfield47,864 people · ~20 km away
- Wildwood35,899 people · ~26 km away
- Florissant52,268 people · ~33 km away
FAQ
What is the population of O'Fallon?
O'Fallon has a population of 85,040 (city proper, latest official figure via GeoNames), making it the #420 biggest city in United States.
What state is O'Fallon in?
O'Fallon is located in Missouri, United States.
Is O'Fallon the capital of United States?
No, the capital of United States is Washington D.C., about 1,182 km away.
Sources & notes
Population refers to the city proper (municipal boundaries), not the metropolitan area. Source: GeoNames (CC BY 4.0), retrieved 2026-07-07. Country data: UN World Population Prospects 2024.
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