Walnut Township is one of ten townships in Marshall County, Indiana, United States.

As of the 2020 census, its population was 2,873 (up from 2,747 at 2010[2]) and it contained 1,140 housing units.

[3] The Argos Izaak Walton League Historic District was listed on the National Register of Historic Places in 2011.

[2] The township contains these two cemeteries: Maple Grove and McGrew.

Walnut Township residents may obtain a free library card from the Argos Public Library in Argos.