| Bridge Name: | Douvenant Viaduct |
| Native Name: | (French: viaduc de Douvenant) |
| Native Name Lang: | French |
| Carries: | Saint-Brieuc - Moncontour line Saint-Brieuc - Saint-Briac line |
| Locale: | Saint-Brieuc |
| Architect: | Louis Auguste Harel de La Noë |
| Length: | 130.8m (429.1feet) |
| Height: | 22.8m (74.8feet) |
| Spans: | 15 |
| Begin: | 1903 |
| Complete: | 1905 |
| Coordinates: | 48.5167°N -2.7183°W |
The Douvenant Viaduct (French: viaduc de Douvenant) is a railway viaduct built between 1903 and 1905 for the Chemin de Fer des Côtes-du-Nord, between the French communes of Saint-Brieuc and Langueux. It was used by the Saint-Brieuc - Moncontour line and the Saint-Brieuc - Saint-Briac line. It was designed by Louis Auguste Harel de La Noë and is the grandest in a series of thirteen "grognet" type viaducts.
The Association des Chemins de Fer des Côtes-du-Nord is constructing a heritage railway line that will use the viaduct.