Marion Township is one of nine townships in Pike County, Indiana, United States.

As of the 2020 census, its population was 683 and it contained 297 housing units.

[3] According to the 2010 census, the township has a total area of 36.11 square miles (93.5 km2), of which 35.41 square miles (91.7 km2) (or 98.06%) is land and 0.7 square miles (1.8 km2) (or 1.94%) is water.

[4] (This list is based on USGS data and may include former settlements.)

The township contains these six cemeteries: Beadles, Bruster Branch, Corn, Flat Creek, Hayes and Walnut Grove.