| Type: | commune |
| County: | Bacău |
| Population Total: | auto |
| Traian | |
| Coordinates: | 46.6333°N 29°W |
Traian is a commune in Bacău County, Western Moldavia, Romania. It is composed of five villages: Bogdănești, Hertioana de Jos, Hertioana-Răzeși, Traian and Zăpodia. It also included Prăjești village until 2005, when it was split off to form a separate commune.