Salem Township is located in Marion County, Illinois. As of the 2010 census, its population was 9,286 and it contained 4,225 housing units.
Salem Township (T2N R2E) is centered at 38ð36'N 88ð59'W (38.619, -88.980). It is traversed northâÂÂsouth by Interstate Route 57 and State Route 37 and eastâÂÂwest by U.S. Route 50. The city of Salem is located in the northeastern part of the township as is most of the Salem Reservoir (El. 166 m). According to the 2010 census, the township has a total area of , of which (or 99.05%) is land and (or 0.95%) is water.