| Mareil-Marly | |
| Commune Status: | Commune |
| Image Coat Of Arms: | Blason ville fr Mareil-Marly (Yvelines).svg |
| Arrondissement: | Saint-Germain-en-Laye |
| Canton: | Saint-Germain-en-Laye |
| Insee: | 78367 |
| Postal Code: | 78750 |
| Mayor: | Dominique Lafon[1] |
| Term: | 2020 - 2026 |
| Intercommunality: | CA Saint Germain Boucles Seine |
| Coordinates: | 48.8825°N 2.0775°W |
| Elevation M: | 120 |
| Elevation Min M: | 42 |
| Elevation Max M: | 161 |
| Area Km2: | 1.77 |
Mareil-Marly (in French pronounced as /maʁɛj maʁli/) is a commune in the Yvelines department in the Île-de-France region in north-central France.
The train station was built in 1882 on the Grande Ceinture line. Since 2022, it is served by Île-de-France tramway Line 13 Express between Saint-Germain-en-Laye and Saint-Cyr-l'École.