| Muya | |
| Other Name: | Муя |
| Source1: | Northern Muya Range |
| Source1 Coordinates: | 55.8256°N 112.5808°W |
| Source1 Elevation: | 1700m (5,600feet) |
| Mouth: | Vitim |
| Mouth Elevation: | 467m (1,532feet) |
| Mouth Location: | Ust-Muya |
| Mouth Coordinates: | 56.4047°N 115.6723°W |
| Subdivision Type1: | Country |
| Subdivision Name1: | Russia |
| Subdivision Type2: | Republic |
| Subdivision Name2: | Buryatia |
| Length: | 365km (227miles) |
| Basin Size: | 11900km2 |
| Pushpin Map: | Russia Buryatia |
| Pushpin Map Caption: | Mouth location in Buryatia, Russia |
The Muya (Russian: Муя) is a left tributary of the Vitim in Buryatia, Russia. It is long and has a drainage basin of .
The area through which the river flows is sparsely populated, the only settlement on the river being Taksimo, with the village of Ust-Muya located where the river flows into the Vitim, nearly opposite from the mouth of the Kuanda in the facing bank.[1] The Muya is navigable for small craft from the Vitim around 70km (40miles) to Taksimo.
The Muya has lent its name to a number of other geographic features, including the Northern Muya Range, the Southern Muya Range, the Muya-Kuanda Depression, as well as the local Muya District.
The longest tributary of the Muya is the long Muyakan on the left.