Union City Township is one of eighteen townships in Allamakee County, Iowa, USA. At the 2010 census, its population was 219.
Union City Township was organized in 1852. The township is named from an early settlement on the north side of the Upper Iowa River above the mouth of French Creek.
Union City Township covers an area of and contains no incorporated settlements. According to the USGS, it contains three cemeteries: Mount Hope, Portland Prairie and Wheatland.