Harmony Township is one of six townships in Union County, Indiana, United States. As of the 2020 census, its population was 527 and it contained 286 housing units.
According to the 2010 census, the township has a total area of , of which (or 89.82%) is land and (or 10.18%) is water.
(This list is based on USGS data and may include former settlements.)
The township contains these two cemeteries: New Hope and Old Bath Springs.