Rockvale Township is located in Ogle County, Illinois. As of the 2010 census, its population was 1,770 and it contained 804 housing units.
Rockvale Township was originally named Brooklyn Township, but changed its name on November 12, 1850.
According to the 2010 census, the township has a total area of , of which (or 97.53%) is land and (or 2.47%) is water.