| Official Name: | Donji Dejan |
| Settlement Type: | Village |
| Pushpin Map: | Serbia |
| Pushpin Label Position: | bottom |
| Subdivision Type: | Country |
| Subdivision Name: |  Serbia |
| Subdivision Type1: | District |
| Subdivision Name1: | Jablanica District |
| Subdivision Type2: | Municipality |
| Subdivision Name2: | Vlasotince |
| Unit Pref: | Imperial |
| Population As Of: | 2002 |
| Population Total: | 497 |
| Timezone: | CET |
| Utc Offset: | +1 |
| Timezone Dst: | CEST |
| Utc Offset Dst: | +2 |
| Coordinates: | 42.975°N 22.2222°W |
Donji Dejan is a village in the municipality of Vlasotince, Serbia. According to the 2002 census, the village has a population of 497 people.[1]