Washington Township is one of twelve townships in Boone County, Indiana.

As of the 2010 census, its population was 1,398 and it contained 547 housing units.

[4] According to the 2010 census, the township has a total area of 35.58 square miles (92.2 km2), of which 35.44 square miles (91.8 km2) (or 99.61%) is land and 0.14 square miles (0.36 km2) (or 0.39%) is water.

[4] The township contains three cemeteries: Bethel, Bethel Hill and Brush Creek.