| Official Name: | Walnut Township, Appanoose County |
| Settlement Type: | Township |
| Subdivision Type: | Country |
| Subdivision Type1: | State |
| Subdivision Type2: | County |
| Subdivision Name2: | Appanoose |
| Area Total Km2: | 80.01 |
| Area Land Km2: | 72.14 |
| Area Water Km2: | 7.87 |
| Unit Pref: | Imperial |
| Population As Of: | 2010 |
| Population Total: | 894 |
| Population Density Km2: | 12.4 |
| Elevation Footnotes: | [1] |
| Elevation M: | 301 |
| Elevation Ft: | 988 |
| Coordinates: | 40.8056°N -92.9308°W |
| Blank Name: | FIPS code |
| Blank Info: | 19-94392[2] |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 0468882 |
Walnut Township is one of eighteen townships in Appanoose County, Iowa, United States. As of the 2010 census, its population was 894.[3]
Walnut Township covers an area of 80km2 and contains two incorporated settlements: Mystic and Rathbun. According to the USGS, it contains six cemeteries: Bohm, Elgin, Forbush, Highland, Shaeffer and Zimmer.