| Official Name: | Union Township |
| Settlement Type: | Township |
| Subdivision Type: | Country |
| Subdivision Type1: | State |
| Subdivision Type2: | County |
| Subdivision Name2: | Crawford |
| Area Total Km2: | 93.15 |
| Area Land Km2: | 92.82 |
| Area Water Km2: | 0.32 |
| Unit Pref: | Imperial |
| Area Total Sq Mi: | 35.96 |
| Area Land Sq Mi: | 35.84 |
| Area Water Sq Mi: | 0.12 |
| Area Water Percent: | 0.34 |
| Population As Of: | 2000 |
| Population Total: | 876 |
| Population Density Km2: | 9.4 |
| Population Density Sq Mi: | 24.4 |
| Elevation M: | 368 |
| Elevation Ft: | 1207 |
| Coordinates: | 41.9106°N -95.5011°W |
| Blank Name: | GNIS feature ID |
| Blank Info: | 0468815 |
Union Township is a township in Crawford County, Iowa, USA. As of the 2000 census, its population was 876.
Union Township covers an area of 35.96sqmi and contains two incorporated settlements: Arion and Dow City. According to the USGS, it contains two cemeteries: Butler and Dow City.
The streams of Buss Creek, Paradise Creek, Welsh Creek and Willow Creek run through this township.