| Official Name: | Zagustay |
| Native Name: | Загустай |
| Settlement Type: | Ulus |
| Pushpin Map: | Russia Buryatia#Russia |
| Subdivision Type: | Country |
| Subdivision Name: | Russia |
| Subdivision Name1: | Republic of Buryatia |
| Subdivision Name3: | Kizhinginsky District |
| Subdivision Type4: | Municipality |
| Utc Offset1: | +8:00 |
| Coordinates: | 51.9667°N 153°W[1] |
Zagustay (ru|Загустай; bua|Загаһатай, Zagahatai) is a rural locality (an ulus) in Kizhinginsky District, Republic of Buryatia, Russia. The population was 1,199 as of 2010.[2] There are 11 streets.
Zagustay is located 68 km east of Kizhinga (the district's administrative centre) by road. Khurtey is the nearest rural locality.[3]