The Râul Negru (; literally meaning "Black River") is a left tributary of the river Olt in Romania. It joins the Olt in Lunca Câlnicului.Raul Negru (jud. Brasov), e-calauza.ro The Râul Negru flows through the villages Lemnia, Lunga, Catalina, Hătuica, Surcea, Telechia, Bita, Reci, Sântionlunca, Ozun, Băcel, Chichiș and Lunca Câlnicului. Its length is and its basin size is .
Tributaries
The following rivers are tributaries to the Râul Negru (from source to mouth):
Left: Pârâul Mare, Brețcu, Stânca Uriașului, Capolna, Ojdula, Pârâul Racilor, Ghelința, Borviz, Zăbala, Fundul Pârâului, Covasna, Pârâul Beldii, Lisnău, Pârâul Satului, Tărlung Right: Lemnia, Estelnic, Cașin, Mărtineni, Mărcușa, Dalnic, Pădureni, Reci, Angheluș
References