Shiloh Valley Township is located in St. Clair County, Illinois. As of the 2010 census, its population was 11,631 and it contained 4,284 housing units. Shiloh Valley Township was originally called Shiloh before its name was changed on an unknown date.
According to the 2010 census, the township has a total area of , of which (or 99.34%) is land and (or 0.66%) is water.