| Baciu | |
| Pushpin Map: | Romania |
| Subdivision Type1: | Country |
| Subdivision Name1: | Romania |
| Subdivision Type2: | Counties |
| Subdivision Name2: | Covasna County |
| Subdivision Type3: | Villages |
| Subdivision Name3: | Dobolii de Jos |
| Length: | 10km (10miles) |
| Mouth: | Olt |
| Mouth Location: | Dobolii de Jos |
| Mouth Coordinates: | 45.766°N 25.7667°W |
| Basin Size: | 18km2 |
The Baciu is a right tributary of the river Olt in Romania. It discharges into the Olt in Dobolii de Jos. Its length is 10km (10miles) and its basin size is 18km2.