| Plesnoy | |
| Commune Status: | Commune |
| Arrondissement: | Langres |
| Canton: | Nogent |
| Insee: | 52392 |
| Postal Code: | 52360 |
| Mayor: | Michel Thenail[1] |
| Term: | 2020 - 2026 |
| Intercommunality: | Grand Langres |
| Coordinates: | 47.8922°N 5.4986°W |
| Elevation M: | 362 |
| Area Km2: | 9.03 |
Plesnoy (in French pronounced as /plɛnwa/) is a commune in the Haute-Marne department in north-eastern France.