O'Fallon, named for wealthy railroad official John O'Fallon, is located in southwestern Illinois in St. Clair County as part of the St Louis metro area about 10 miles east of East St. Louis along Interstate 64.
The area's settlement began in the 1850s when the Ohio and Mississippi (now the Baltimore and Ohio) Railroad built a depot and water tower here. Coal mining and the rich surrounding farm land spurred its growth and by 1874 the village became incorporated. Today, Scott Air Force Base provides a significant boost to the area's economy.