Nameoki Township is located in Madison County, Illinois, in the United States. As of the 2010 census, its population was 12,685 and it contained 5,352 housing units.
Nameoki is derived from a Native American name meaning "smoky".
According to the 2010 census, the township has a total area of , of which (or 82.03%) is land and (or 17.97%) is water.