Washington Township is one of ten townships in Knox County, Indiana. As of the 2020 census, its population was 2,256 (slightly down from 2,286 at 2010) and it contained 1,040 housing units. It contains the census-designated place of Ragsdale.
It is named for George Washington.
Enoco Coal Mine was added to the National Register of Historic Places in 2010.
According to the 2010 census, the township has a total area of , of which (or 99.49%) is land and (or 0.49%) is water.
It is in the North Knox School Corporation.