| Official Name: | Lynn Township Posey County |
| Settlement Type: | Township |
| Subdivision Type: | Country |
| Subdivision Name: | United States |
| Subdivision Type1: | State |
| Subdivision Name1: | Indiana |
| Subdivision Type2: | County |
| Subdivision Name2: | Posey |
| Government Type: | Indiana township |
| Area Total Km2: | 115.79 |
| Area Land Km2: | 112.99 |
| Area Water Km2: | 2.8 |
| Area Total Sq Mi: | 44.71 |
| Area Land Sq Mi: | 43.63 |
| Area Water Sq Mi: | 1.08 |
| Population As Of: | 2020 |
| Population Total: | 810 |
| Population Density Sq Mi: | auto |
| Elevation Footnotes: | [1] |
| Elevation M: | 132 |
| Elevation Ft: | 433 |
| Coordinates: | 38.0469°N -87.9261°W |
| Blank Name: | FIPS code |
| Blank Info: | 18-45450[2] |
| Blank1 Name: | GNIS feature ID |
| Blank1 Info: | 453585 |
Lynn Township is one of ten townships in Posey County, Indiana. As of the 2020 census, its population was 810.[3]
Lynn Township was organized in 1817.[4] The township bears the name of Dan Lynn, a state legislator.[5]
It is within the Metropolitan School District of Mt. Vernon,[6] which operates Mount Vernon High School.