| Bayandun District | |
| Native Name: | Баяндун сум |
| Native Name Lang: | mn |
| Settlement Type: | District |
| Subdivision Type: | Country |
| Subdivision Name: | Mongolia |
| Subdivision Type1: | Province |
| Subdivision Name1: | Dornod Province |
| Area Total Km2: | 6,237 |
| Timezone: | UTC + 8 |
| Utc Offset: | +8 |
Bayandun (Mongolian: Баяндун is a sum (district) of Dornod Province in eastern Mongolia. In 2009, its population was 2,936.[1]