| Boissy-sous-Saint-Yon | |
| Commune Status: | Commune |
| Image Coat Of Arms: | Blason ville fr Boissy-sous-Saint-Yon (Essonne).svg |
| Coordinates: | 48.5586°N 2.2086°W |
| Insee: | 91085 |
| Postal Code: | 91790 |
| Arrondissement: | Étampes |
| Canton: | Arpajon |
| Intercommunality: | Entre Juine et Renarde |
| Mayor: | Jean-Marc Pichon[1] |
| Term: | 2023 - 2026 |
| Elevation Min M: | 69 |
| Elevation Max M: | 156 |
| Area Km2: | 8.04 |
Boissy-sous-Saint-Yon (in French pronounced as /bwasi su sɛ̃.t‿jɔ̃/, literally Boissy under Saint-Yon) is a commune in the Essonne department in Île-de-France in northern France.
Inhabitants of Boissy-sous-Saint-Yon are known as Buxéens in French.