| Yanamayo | |
| Name Etymology: | Quechua |
| Subdivision Type1: | Country |
| Subdivision Name1: | Peru |
| Subdivision Type3: | Region |
| Subdivision Name3: | Ancash Region, Huánuco Region |
| Mouth: | Marañón River |
| Tributaries Left: | Pomapampa, Pampachara |
| Tributaries Right: | Tinkuq, San Nicolás |
Yanamayo (possibly from Quechua yana black, mayu river,[1] "black river") is a river in the Ancash Region in Peru. It flows along the border between the provinces Carlos Fermín Fitzcarrald and Mariscal Luzuriaga and empties into the Marañón River as a left tributary. The confluence is on the border of the districts Eleazar Guzman Barron, San Nicolás and Canchabamba.[2]