| Pustnic | |
| Pushpin Map: | Romania |
| Subdivision Type1: | Country |
| Subdivision Name1: | Romania |
| Subdivision Type2: | Counties |
| Subdivision Name2: | Harghita County |
| Subdivision Type3: | Villages |
| Subdivision Name3: | Șoimeni, Păuleni-Ciuc |
| Length: | 15km (09miles) |
| Mouth: | Olt |
| Mouth Coordinates: | 46.3716°N 25.7664°W |
| Basin Size: | 46km2 |
| Tributaries Left: | Orociu, Șumuleu |
The Pustnic is a left tributary of the river Olt in Romania. It flows into the Olt near Miercurea Ciuc.[1] Its length is 15km (09miles) and its basin size is 46km2.