| Official Name: | Buchanan Township |
| Settlement Type: | Township |
| Subdivision Type: | Country |
| Subdivision Type1: | State |
| Subdivision Type2: | County |
| Subdivision Name2: | Atchison |
| Area Total Km2: | 108.84 |
| Area Land Km2: | 106.84 |
| Area Water Km2: | 2.00 |
| Area Water Percent: | 1.84 |
| Population As Of: | 2010 |
| Population Total: | 83 |
| Population Density Km2: | 0.8 |
| Elevation Footnotes: | [1] |
| Elevation M: | 277 |
| Elevation Ft: | 909 |
| Coordinates: | 40.5406°N -95.6211°W |
| Blank Name: | FIPS code |
| Blank Info: | 29-09244[2] |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 0766231 |
Buchanan Township is one of eleven townships in Atchison County, Missouri, United States. At the 2010 census, its population was 83.[3] The northwest corner of the township is the northwest corner of the entire state.
Buchanan Township was established in 1858, and named after James Buchanan, the 15th President of the United States.[4]
Buchanan Township covers an area of and contains no incorporated settlements. Buchanan Township has two cemeteries: Union, and Clayton-Lewis. Greys Lake is within this township.