Broadwell Township is located in Logan County, Illinois. At the 2010 census, its population was 3,549 and it contained 256 housing units. Most of the residents of the township are inmates at the Lincoln Correctional Center and Logan Correctional Center.
According to the 2010 census, the township has a total area of , of which (or 98.50%) is land and (or 1.50%) is water.