| Official Name: | Udinsk |
| Native Name: | Удинск |
| Settlement Type: | Selo |
| Pushpin Map: | Russia Buryatia#Russia |
| Subdivision Type: | Country |
| Subdivision Name: | Russia |
| Subdivision Name1: | Republic of Buryatia |
| Subdivision Name3: | Khorinsky District |
| Subdivision Type4: | Municipality |
| Utc Offset1: | +8:00 |
| Postal Code: | 671420 |
| Coordinates: | 52.1333°N 121°W[1] |
Udinsk (Russian: Удинск; Buriat: Хахирай Үртөө, Khakhirai Ürtöö) is a rural locality (a selo) in Khorinsky District, Republic of Buryatia, Russia. The population was 719 as of 2010.[2] There are 10 streets.
Udinsk is located 43 km west of Khorinsk (the district's administrative centre) by road. Tarbagatay is the nearest rural locality.[3]