Etna Township is one of seventeen townships in Kosciusko County, Indiana. As of the 2020 census, its population was 1,500 (a tiny decline of 1,503 from 2010) and it contained 537 housing units.
According to the 2010 census, the township has a total area of , of which (or 98.97%) is land and (or 1.03%) is water.