| Câlnău | |
| Name Other: | Salcia |
| Pushpin Map: | Romania |
| Subdivision Type1: | Country |
| Subdivision Name1: | Romania |
| Subdivision Type2: | Counties |
| Subdivision Name2: | Buzău County |
| Length: | 57km (35miles) |
| Source1: | Vaca Rea Hill |
| Source1 Coordinates: | 45.5417°N 26.7603°W |
| Source1 Elevation: | 730m (2,400feet) |
| Mouth: | Buzău |
| Mouth Location: | Gura Câlnăului |
| Mouth Coordinates: | 45.17°N 26.8339°W |
| Mouth Elevation: | 84m (276feet) |
| Basin Size: | 208km2 |
| Tributaries Right: | Hârboca |
The Câlnău is a left tributary of the river Buzău in Romania. It discharges into the Buzău in Gura Câlnăului, near the city Buzău.[1] Its length is 57km (35miles) and its basin size is 208km2. The upper reach of the river is also known as Salcia. The following villages are situated along the river Câlnău, from source to mouth: Valea Salciei, Modreni, Costomiru, Batogu, Murgești, Racovițeni, Petrișoru, Vadu Sorești, Fundeni, Zărnești, Sudiți, Coconari, Aliceni, Zilișteanca, Poșta Câlnău, Potârnichești and Gura Câlnăului.
The following rivers are tributaries to the river Câlnău: