As of the 2020 census, its population was 3,365 (down from 3,493 at 2010[3]) and it contained 1,563 housing units.

The first settler, Thomas Henton, arrived in Washington Township in 1838 and built a cabin upon a hill.

[3] The Wabash River defines the township's northern border.

(This list is based on USGS data and may include former settlements.)

The township contains these four cemeteries: Crider, Rankin, Salem and Sharpee.