| Chalo-Saint-Mars | |
| Commune Status: | Commune |
| Image Coat Of Arms: | Blason ville fr Chalo Saint Mars (Ile de France).svg |
| Coordinates: | 48.4267°N 2.067°W |
| Insee: | 91130 |
| Postal Code: | 91780 |
| Arrondissement: | Étampes |
| Canton: | Étampes |
| Intercommunality: | CA Étampois Sud Essonne |
| Mayor: | Xavier Guiomar[1] |
| Term: | 2020 - 2026 |
| Elevation Min M: | 81 |
| Elevation Max M: | 152 |
| Area Km2: | 28.67 |
Chalo-Saint-Mars (pronounced as /fr/) is a commune in the Essonne department in Île-de-France in northern France.
Inhabitants of Chalo-Saint-Mars are known as Chaloins.