| Official Name: | Walnut, Indiana |
| Pushpin Map: | Indiana#USA |
| Pushpin Label: | Walnut |
| Pushpin Label Position: | top |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Indiana |
| Subdivision Type2: | County |
| Subdivision Name2: | Marshall |
| Subdivision Type3: | Township |
| Subdivision Name3: | Walnut |
| Coordinates: | 41.1761°N -86.2119°W |
| Elevation Footnotes: | [1] |
| Elevation Ft: | 850 |
| Postal Code Type: | ZIP code |
| Postal Code: | 46501 |
| Blank Name: | FIPS code |
| Blank Info: | 18-79802[2] |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 445403 |
Walnut is an unincorporated community in Walnut Township, Marshall County, Indiana.
Walnut was originally called Fredericksburg, and under the latter name was laid out and platted in 1866. When the railroad was built through the settlement in 1868, it was renamed Walnut, after Walnut Township.[3] A post office was established as Walnut in 1869, and remained in operation until it was discontinued in 1906.[4]
Walnut is located at 41.1761°N -86.2119°W.