| Ruja | |
| Pushpin Map: | Romania |
| Subdivision Type1: | Country |
| Subdivision Name1: | Romania |
| Subdivision Type2: | Counties |
| Subdivision Name2: | Bacău County |
| Length: | 8km (05miles) |
| Source1 Coordinates: | 46.5136°N 26.5139°W |
| Source1 Elevation: | 496m (1,627feet) |
| Mouth: | Tazlăul Sărat |
| Mouth Location: | Șesuri |
| Mouth Coordinates: | 46.5117°N 26.5778°W |
| Mouth Elevation: | 345m (1,132feet) |
| Basin Size: | 13km2 |
The Ruja is a left tributary of the river Tazlăul Sărat in Romania.[1] It discharges into the Tazlăul Sărat in Șesuri. Its length is 8km (05miles) and its basin size is 13km2.