Downs Township is located in McLean County, Illinois. At the 2010 census, its population was 1,266 and it contained 483 housing units. Downs Township was originally named Savanna Township, but it was changed on May 17, 1858.
According to the 2010 census, the township has a total area of , of which (or 99.98%) is land and (or 0.02%) is water.