Union Township is one of seven townships in Perry County, Indiana, United States. As of the 2020 census, its population was 591 and it contained 287 housing units.

Historical population

Census	Pop.	Note	%±
1890	1,616		—
1900	1,490		−7.8%
1910	1,432		−3.9%
1920	1,276		−10.9%
1930	896		−29.8%
1940	960		7.1%
1950	737		−23.2%
1960	612		−17.0%
1970	540		−11.8%
1980	541		0.2%
1990	512		−5.4%
2000	523		2.1%
2010	557		6.5%
2020	591		6.1%
Source: US Decennial Census

The Rockhouse Cliffs Rock Shelters was listed on the National Register of Historic Places in 1986.

According to the 2010 census, the township has a total area of 43.12 square miles (111.7 km), of which 42.27 square miles (109.5 km) (or 98.03%) is land and 0.85 square miles (2.2 km) (or 1.97%) is water.

• Derby at 38°01′49″N 86°31′38″W / 38.03034°N 86.527202°W / 38.03034; -86.527202
• Dexter at 38°03′33″N 86°28′43″W / 38.05923°N 86.47859°W / 38.05923; -86.47859
• Magnet at 38°05′48″N 86°27′48″W / 38.09673°N 86.463312°W / 38.09673; -86.463312
• Mount Pleasant at 38°07′18″N 86°31′04″W / 38.121729°N 86.517759°W / 38.121729; -86.517759

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

The township contains these seven cemeteries: Badger, Derby, Horton, Old Chapel, Phelps, Stephenson and Talley.

• Indiana State Road 37

• Perry Central Community School Corporation

• State House District 73
• State House District 74
• State Senate District 47

• "Union Township, Perry County, Indiana". Geographic Names Information System. United States Geological Survey, United States Department of the Interior. Retrieved November 21, 2009.
• United States Census Bureau 2009 TIGER/Line Shapefiles
• IndianaMap

• Indiana Township Association
• United Township Association of Indiana
• City-Data.com page for Union Township