| Official Name: | Ust-Muya |
| Native Name: | Усть-Муя |
| Settlement Type: | Settlement |
| Pushpin Map: | Russia Buryatia#Russia |
| Subdivision Type: | Country |
| Subdivision Name: | Russia |
| Subdivision Name1: | Republic of Buryatia |
| Subdivision Name3: | Muysky District |
| Subdivision Type4: | Municipality |
| Utc Offset1: | +8:00 |
| Coordinates: | 56.4°N 152°W[1] |
Ust-Muya (Russian: Усть-Муя; Buriat: Муяын Адаг, Muiayn Adag) is a rural locality (a settlement) in Muysky District, Republic of Buryatia, Russia. The population was 632 in 2010.[2] There are 14 streets.
Ust-Muya is located east of Taksimo (the district's administrative centre) by road. Muya is the nearest rural locality.[3]