| Fay-lès-Marcilly | |
| Commune Status: | Commune |
| Arrondissement: | Nogent-sur-Seine |
| Canton: | Saint-Lyé |
| Insee: | 10146 |
| Postal Code: | 10290 |
| Mayor: | Jérémy Flogny[1] |
| Term: | 2020 - 2026 |
| Intercommunality: | Orvin et Ardusson |
| Coordinates: | 48.4036°N 3.6033°W |
| Elevation M: | 162 |
| Area Km2: | 5.76 |
Fay-lès-Marcilly (in French pronounced as /fɛ lɛ maʁsiji/) is a commune in the Aube department in north-central France.