O'Fallon, Illinois

O'Fallon, Illinois
City
The Illinois Central Railroad Downtown Caboose
Flag Seal
Nickname:  "O-Town"
Location of O'Fallon in St. Clair County, Illinois.
Coordinates: 38°35′46″N 89°54′56″W / 38.59611°N 89.91551°W / 38.59611; -89.91551
Country	United States
State	Illinois
County	St. Clair
Township	O'Fallon
Government
• Type	Home rule[1]
• Mayor	Herb Roach
Area [2]
• Total	15.71 sq mi (40.67 km2)
• Land	15.59 sq mi (40.39 km2)
• Water	0.11 sq mi (0.29 km2)
Elevation [3]	541 ft (165 m)
Population  (2020)
• Total	32,289
• Density	2,070.60/sq mi (799.48/km2)
Time zone	UTC−6 (CST)
• Summer (DST)	UTC−5 (CDT)
ZIP code(s)	62269
Area code	618
FIPS code	17-55249
GNIS feature ID	2395302[3]
Wikimedia Commons	O'Fallon, Illinois
Website	ofallon.org

O'Fallon is a city in St. Clair County, Illinois, United States. The 2020 census listed the population at 32,289. The city is the second largest city in the Metro East region of the St. Louis metropolitan area and Southern Illinois. It sits 5 miles (8.0 km) from Scott Air Force Base and 18 miles (29 km) from Downtown St. Louis.

Like its namesake in St. Charles County, Missouri, O'Fallon is part of the St. Louis metro area. This makes O'Fallon (along with the two Troys in Illinois and Missouri) one of the few pairs of like-named municipalities to be part of the same metro region.