Union Township is one of fourteen townships in Madison County, Indiana, United States. As of the 2010 census, its population was 8,898 and it contained 4,004 housing units.
Union Township was organized in 1830. It was likely named in commemoration of the federal union of the United States.
According to the 2010 census, the township has a total area of , of which (or 99.65%) is land and (or 0.35%) is water.
The township contains these three cemeteries: Bronnenberg, Clem and Keesling.
Union Township residents may obtain a free library card from the Anderson Public Library in Anderson.