St. Clair Township is located in St. Clair County, Illinois.

As of the 2010 census, its population was 35,498 and it contained 15,366 housing units.

[2] St. Clair Township formed from a portion of Belleville Township on October 5, 1885.

According to the 2010 census, the township has a total area of 20.52 square miles (53.1 km2), of which 20.17 square miles (52.2 km2) (or 98.29%) is land and 0.35 square miles (0.91 km2) (or 1.71%) is water.

This St. Clair County, Illinois location article is a stub.