Marion Township is one of twelve townships in Boone County, Indiana.

As of the 2010 census, its population was 1,233 and it contained 506 housing units.

[4] According to the 2010 census, the township has a total area of 45.94 square miles (119.0 km2), of which 45.93 square miles (119.0 km2) (or 99.98%) is land and 0.01 square miles (0.026 km2) (or 0.02%) is water.

[4] The township contains two cemeteries: Bethel and Parr-Jones.