Union Township is one of nine townships in Crawford County, Indiana. As of the 2020 census, its population was 734 and it contained 384 housing units.
The Potts Creek Rockshelter was listed on the National Register of Historic Places in 1987.
According to the 2010 census, the township has a total area of , all land.
(This list is based on USGS data and may include former settlements.)
The township contains five cemeteries: Doan, Fessler, Goad, Hedden, Mifflin, and Keysacker.