Union Township is one of twelve townships in Delaware County, Indiana. According to the 2010 census, its population was 2,838 and it contained 1,260 housing units.
Felt's Farm and the Mount Zion Methodist Episcopal Church are listed on the National Register of Historic Places.
According to the 2010 census, the township has a total area of , of which (or 98.95%) is land and (or 1.01%) is water.
(This list is based on USGS data and may include former settlements.)
The township contains three cemeteries: Leaird, Mount Zion Church and Union.
It is in the Delaware Community School Corporation.