| Stemnic | |
| Pushpin Map: | Romania |
| Subdivision Type1: | Country |
| Subdivision Name1: | Romania |
| Subdivision Type2: | Counties |
| Subdivision Name2: | Vaslui County |
| Subdivision Type3: | Villages |
| Subdivision Name3: | Pungești, Ivănești, Pușcași |
| Length: | 32km (20miles) |
| Mouth: | Bârlad |
| Mouth Coordinates: | 46.6693°N 27.666°W |
| Basin Size: | 150km2 |
| Tributaries Left: | Fundul Negru |
| Tributaries Right: | Fâstâca |
The Stemnic is a right tributary of the river Bârlad in Romania. It discharges into the Bârlad near Bălteni. Its length is 32km (20miles) and its basin size is 150km2.