Washington Township is one of twelve townships in Jackson County, Indiana, United States. As of the 2020 census, its population was 1,231 and it contained 477 housing units.
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. The stream of Horse Lick runs through this township.
The township contains one cemetery, Chestnut Ridge.