O'Fallon city, Missouri
Official LSAD Designation: O'Fallon city • Census GEOID: 2954074
• St. Charles County
Demographics & Population Profile
Population and demographics for O'Fallon city.
| Demographic Variable | Estimate / Count | Margin of Error | Period | Source |
|---|---|---|---|---|
| Total Population (2025 PEP Estimate) | 96,101 | — | 2025 | Census |
| Median Age | 38.4 yrs | ±0.7 | 2020-2024 | Census ACS 5-Year 2024 |
| Total Households | 35,471 | ±720 | 2020-2024 | Census ACS 5-Year 2024 |
Source: U.S. Census Bureau (PEP, ACS 5-Year).