Dunham Township is located in McHenry County, Illinois, USA. As of the 2010 census, its population was 2,844 and it contained 1,035 housing units. It includes southern portions of Harvard, most of the city being in Chemung Township, and part of the census-designated place of Chemung.
Dunham Township changed its name from Byron Township on December 28, 1850, to avoid confusion with Byron Township and to honor a resident, Solomon J. Dunham.
According to the 2010 census, the township has a total area of , of which (or 99.97%) is land and (or 0.03%) is water.