Cruger Township is located in Woodford County, Illinois. As of the 2010 census, its population was 1,687 and it contained 593 housing units. Cruger Township formed from Olio Township on September 14, 1869.
According to the 2010 census, the township has a total area of , of which (or 99.77%) is land and (or 0.23%) is water.