| Official Name: | Mongoy |
| Native Name: | Монгой |
| Settlement Type: | Settlement |
| Pushpin Map: | Russia Buryatia#Russia |
| Subdivision Type: | Country |
| Subdivision Name: | Russia |
| Subdivision Name1: | Republic of Buryatia |
| Subdivision Name3: | Bauntovsky District |
| Subdivision Type4: | Municipality |
| Utc Offset1: | +8:00 |
| Coordinates: | 53.9667°N 162°W[1] |
Mongoy (Russian: Монгой) is a rural locality (a settlement) in Bauntovsky District, Republic of Buryatia, Russia. The population was 205 as of 2010.[2] There are 8 streets.
Mongoy is located by the Amalat river in the Vitim Plateau, 80 km southeast of Bagdarin (the district's administrative centre).[3]