| Piz Riein | |
| Elevation M: | 2762 |
| Prominence M: | 81 |
| Prominence Ref: | [1] |
| Parent Peak: | Piz Fess |
| Map: | Switzerland |
| Location: | Graubünden, Switzerland |
| Range: | Lepontine Alps |
| Coordinates: | 46.7405°N 9.2929°W |
Piz Riein is a mountain of the Lepontine Alps, situated south-east of Ilanz in the canton of Graubünden. It lies on the range between the Val Lumnezia and Safiental, named Cadeina dil Signina.