Washington Township is one of twelve townships in Rush County, Indiana. As of the 2020 census, its population was 414 and it contained 195 housing units.
The Hall-Crull Octagonal House was listed on the National Register of Historic Places in 1984.
According to the 2010 census, the township has a total area of , all land.
(This list is based on USGS data and may include former settlements.)