Haddon Township is one of nine townships in Sullivan County, Indiana, United States.

As of the 2020 census, its population was 3,762 and it contained 780 housing units.

[1] According to the 2010 census, the township has a total area of 71.47 square miles (185.1 km2), of which 71.22 square miles (184.5 km2) (or 99.65%) is land and 0.25 square miles (0.65 km2) (or 0.35%) is water.

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

The township contains these thirty two cemeteries: Alsman, Arnett, Bethlehem, Benefiel, Booker, Boone, Boyle, Carlisle Old Town, Cartwright, Dooley, Duncan, Engle, Hackett, Haddon, Harper, Independent Order of Odd Fellows, Land, Ledgerwood, Lewis, Loudermilk, McCammon, Mccammon #1, Neil Paxton, Providence, Purcell, Skidmore, Shepard, Snyder, Trimble, Vester, Wilson, and Walters.