| Official Name: | Walnut Township, Missouri |
| Settlement Type: | Township |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Missouri |
| Subdivision Type2: | County |
| Subdivision Name2: | Adair |
| Area Total Km2: | 134.89 |
| Area Land Km2: | 134.88 |
| Area Water Km2: | 0.01 |
| Area Water Percent: | 0.01 |
| Population As Of: | 2010 |
| Population Total: | 257 |
| Population Density Km2: | 1.9 |
| Elevation Footnotes: | [1] |
| Elevation M: | 290 |
| Elevation Ft: | 951 |
| Coordinates: | 40.0839°N -92.7642°W |
| Blank Name: | FIPS code |
| Blank Info: | 29-76786[2] |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 0766218 |
Walnut Township is one of ten townships in Adair County, Missouri, United States. At the 2010 census, its population was 257.[3] Walnut Township was named from the old-growth forests of walnut it contained at the time of settlement.[4]
Walnut Township covers an area of 134.9km2[3] and contains no incorporated settlements. It contains two cemeteries: Cheeseman and Hall.
The streams of Little Mussel Creek and Little Walnut Creek run through this township.