O'Fallon Township is located in St. Clair County, Illinois. As of the 2010 census, its population was 26,053 and it contained 10,338 housing units.
Geography According to the 2010 census, the township has a total area of , of which (or 98.16%) is land and (or 1.84%) is water.
Demographics
References
External links City-data.com St. Clair County Official Site Illinois State Archives