| Septeuil | |
| Commune Status: | Commune |
| Arrondissement: | Mantes-la-Jolie |
| Canton: | Bonnières-sur-Seine |
| Insee: | 78591 |
| Postal Code: | 78790 |
| Mayor: | Dominique Riviere[1] |
| Term: | 2020 - 2026 |
| Intercommunality: | Pays houdanais |
| Coordinates: | 48.8933°N 1.6822°W |
| Elevation M: | 70 |
| Elevation Min M: | 52 |
| Elevation Max M: | 165 |
| Area Km2: | 9.40 |
| Website: | http://www.mairie-septeuil.fr/ |
Septeuil (in French pronounced as /sɛptœj/) is a commune in the Yvelines department in the Île-de-France region in north-central France.
Septeuil is traversed by a small river, la Flexanville. This waterway flows through eight other communes for a total distance of . The Flexanville is a tributary of the Vaucouleurs which in turn empties into the Seine.