| Official Name: | Cass Township, Boone County |
| Settlement Type: | Township |
| Subdivision Type: | Country |
| Subdivision Type1: | State |
| Subdivision Type2: | County |
| Subdivision Name2: | Boone |
| Area Total Km2: | 47.55 |
| Area Land Km2: | 46.74 |
| Area Water Km2: | 0.81 |
| Unit Pref: | Imperial |
| Area Total Sq Mi: | 18.36 |
| Area Land Sq Mi: | 18.05 |
| Area Water Sq Mi: | 0.31 |
| Population As Of: | 2000 |
| Population Total: | 668 |
| Population Density Km2: | 14.3 |
| Population Density Sq Mi: | 37 |
| Elevation Footnotes: | [1] |
| Elevation M: | 304 |
| Elevation Ft: | 997 |
| Coordinates: | 41.9061°N -93.9°W |
| Blank Name: | FIPS code |
| Blank Info: | 19-90489[2] |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 0467537 |
Cass Township is one of seventeen townships in Boone County, Iowa, United States. As of the 2000 census, its population was 668.
Cass Township was established in 1858. It is named for Lewis Cass.[3]
Cass Township covers an area of 18.36sqmi and contains no incorporated settlements. According to the USGS, it contains two cemeteries: Liberty and State Hospital.