| Marignieu | |
| Commune Status: | Commune |
| Arrondissement: | Belley |
| Canton: | Belley |
| Insee: | 01234 |
| Postal Code: | 01300 |
| Mayor: | Pascal Demange[1] |
| Term: | 2020 - 2026 |
| Coordinates: | 45.7978°N 5.7219°W |
| Elevation M: | 358 |
| Elevation Min M: | 309 |
| Elevation Max M: | 503 |
| Area Km2: | 3.55 |
Marignieu (in French pronounced as /maʁiɲø/) is a commune in the Ain department in eastern France.