Browse / United States / Missouri / O'Fallon
O'Fallon
Missouricity
O'Fallon
Total population
95,363
Median home value
$348,200
Bachelor's+
Median income
$113,996
Founded
1856
Demographic figures from US Census Bureau · ACS 5-year estimates. Overview below cites Wikipedia and may reference a different year.
City facts
Facts from Wikidata (CC0).
Overview
O'Fallon is a city in St. Charles County, Missouri, United States. It is part of the St. Louis metropolitan statistical area, along Interstates 64 and 70 between Lake St. Louis and St. Peters. As of the 2020 census, O'Fallon had a population of 91,316, making it St. Louis's most populous suburb as well as the most populous municipality in St. Charles County and the 7th-most populous in Missouri. O'Fallon's namesake in St. Clair County, Illinois, is also part of the St. Louis region. The two cities are one of the few pairs of same-named municipalities to be part of the same metro area.
Read more on WikipediaHistory & geography
History
O'Fallon was founded in 1856 by Nicholas Krekel. The community was named by Krekel's older brother, Judge Arnold Krekel, after John O'Fallon, the president of the North Missouri Railroad. A post office called O'Fallon has been in operation since 1859 with Nicholas Krekel as first postmaster. The St. Mary's Institute of O'Fallon was listed on the National Register of Historic Places in 2007. In 2006, Money magazine named O'Fallon 39th in its "Best 100 Places to Live". The magazine also ranked O'Fallon 68th out of 100 in 2008, 26th out of 100 in 2010, and 42nd out of 100 in 2017.
Geography
According to the United States Census Bureau, the city has an area of , of which are land and is covered by water. O'Fallon has a humid subtropical climate (Köppen Cfa). Summers are hot and humid, while winters are moderately cold.
Excerpted from the corresponding Wikipedia article (CC BY-SA).
Demographics & economy
Race & ethnicity
Source: US Census Bureau — American Community Survey, 5-year estimates.
Geography
Coordinates & boundaries from the US Census TIGER/Line shapefiles.
Climate
Current forecast
Forecast for O'Fallon, MO from NOAA NWS API.
Air quality
Industrial & pollution facilities
Natural hazard risk
Health (adults)
Age-adjusted prevalence estimates from CDC PLACES (latest release).
Walkability
Amenities nearby
Wildlife & biodiversity
Schools
Largest nearby schools
- FRANCIS HOWELL HIGHHigh · ST CHARLES · 1,835 students · 19.9:1 ratio
- FRANCIS HOWELL CENTRAL HIGHHigh · ST CHARLES · 1,805 students · 19.4:1 ratio
- FT. ZUMWALT WEST HIGHHigh · O'FALLON · 1,778 students · 14.7:1 ratio
- FRANCIS HOWELL NORTH HIGHHigh · ST CHARLES · 1,679 students · 18.7:1 ratio
- TIMBERLAND HIGHHigh · WENTZVILLE · 1,676 students · 15.4:1 ratio
- LIBERTY HIGH SCHOOLHigh · LAKE ST. LOUIS · 1,586 students · 17.6:1 ratio
- FT. ZUMWALT NORTH HIGHHigh · O'FALLON · 1,497 students · 13.7:1 ratio
- FT. ZUMWALT SOUTH HIGHHigh · ST PETERS · 1,334 students · 14.2:1 ratio
Public K–12 schools within ~10 mi from Urban Institute Education Data Portal (NCES Common Core of Data, 2022).
Earthquake history
Photos
Sights & places nearby
Notable people from here
Nearby places in Missouri
Geography & sun
Elevation, sunrise/sunset and daylight from Open-Meteo. Solar climatology from NASA POWER.
Nearby airports
Public attention
Pageview totals from the Wikimedia Pageviews API.
Books about O'Fallon
Search results from Open Library.
Recent natural events nearby
Ground air-quality sensors
Recently spotted species
Research-grade observations from iNaturalist (within ~15 mi).
Nearest stream gauge
Live readings from USGS NWIS · measured 2026-10-16 05:05 UTC.
Events
Gallery
Sources
- • Wikipedia
- • US Census Bureau (ACS 5-year estimates)
- • NOAA National Weather Service
- • Wikidata
- • USGS NWIS (water data)
- • NCES via Urban Institute Education Data Portal
- • iNaturalist
- • CDC PLACES
- • Open-Meteo / sunrise-sunset.org
- • Wikipedia Pageviews API
- • Open Library