| Estelnic | |
| Pushpin Map: | Romania |
| Subdivision Type1: | Country |
| Subdivision Name1: | Romania |
| Subdivision Type2: | Counties |
| Subdivision Name2: | Covasna County |
| Subdivision Type3: | Villages |
| Subdivision Name3: | Estelnic |
| Source1: | Nemira Mountains |
| Mouth: | Râul Negru |
| Mouth Location: | near Târgu Secuiesc |
| Mouth Coordinates: | 46.005°N 26.1995°W |
| Tributaries Left: | Lutoasa |
| Tributaries Right: | Valea Scurtă |
The Estelnic is a right tributary of the Râul Negru in Romania. It flows into the Râul Negru near the village Lunga, east of Târgu Secuiesc.[1] Its length is 20km (10miles) and its basin size is 89km2.