Johnson Township is one of eleven townships in LaGrange County, Indiana. As of the 2020 census, its population was 3,546 (up from 3,392 at 2010[4]) and it contained 2,076 housing units.
According to the 2010 census, the township has a total area of 35.63 square miles (92.3 km2), of which 33.27 square miles (86.2 km2) (or 93.38%) is land and 2.36 square miles (6.1 km2) (or 6.62%) is water.[4]