Washington Township is a township in Doniphan County, Kansas, United States. As of the 2020 census, its population was 2,927.
Washington Township was organized in 1855.
Washington Township covers an area of and contains two incorporated settlements: Elwood and Wathena. According to the USGS, it contains two cemeteries: Belmont and Tambor.
The streams of Duncan Creek and Peters Creek run through this township.