| Official Name: | Tsagan-Usun |
| Native Name: | Цаган-Усун |
| Settlement Type: | Selo |
| Pushpin Map: | Russia Buryatia#Russia |
| Subdivision Type: | Country |
| Subdivision Name: | Russia |
| Subdivision Name1: | Republic of Buryatia |
| Subdivision Name3: | Dzhidinsky District |
| Subdivision Type4: | Municipality |
| Utc Offset1: | +8:00 |
| Coordinates: | 50.4333°N 107°W[1] |
Tsagan-Usun (ru|Цаган-Усун; bua|Сагаан уһан, Sagaan uhan) is a rural locality (a selo) in Dzhidinsky District, Republic of Buryatia, Russia. The population was 276 as of 2010.[2] There are 6 streets.
Tsagan-Usun is located 74 km southeast of Petropavlovka (the district's administrative centre) by road. Naushki is the nearest rural locality.[3]