| Official Name: | Jefferson Township |
| Settlement Type: | Township |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Indiana |
| Subdivision Type2: | County |
| Subdivision Name2: | Jay |
| Government Type: | Indiana township |
| Area Total Sq Mi: | 35.16 |
| Area Land Sq Mi: | 35.13 |
| Area Water Sq Mi: | 0.03 |
| Area Water Percent: | 0.09 |
| Population As Of: | 2020 |
| Population Footnotes: | [1] |
| Population Total: | 684 |
| Population Density Sq Mi: | auto |
| Elevation M: | 302 |
| Elevation Ft: | 991 |
| Coordinates: | 40.35°N -85.0753°W |
| Blank Name: | GNIS feature ID |
| Blank Info: | 0453488 |
Jefferson Township is one of twelve townships in Jay County, Indiana, United States. As of the 2020 census, its population was 684 (down from 770 at 2010[2]) and it contained 292 housing units.
Jefferson Township was organized in 1837.[3]
According to the 2010 census, the township has a total area of, of which (or 99.91%) is land and (or 0.09%) is water.[2] The streams of Bost Run, Como Run, Jeff Run, Jutte Run, New Mount Run and Vale Run run through this township.
The township contains seven cemeteries: Bost, Flesher, New Mount Pleasant, Powers, Stephens, Stratton and Wentz.