| Official Name: | Zir Daj |
| Native Name: | زيردج |
| Settlement Type: | village |
| Pushpin Map: | Iran |
| Mapsize: | 150px |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Name1: | Sistan and Baluchestan |
| Subdivision Type2: | County |
| Subdivision Name2: | Chabahar |
| Subdivision Type3: | Bakhsh |
| Subdivision Name3: | Central |
| Subdivision Type4: | Rural District |
| Subdivision Name4: | Pir Sohrab |
| Population As Of: | 2006 |
| Population Total: | 203 |
| Population Density Km2: | auto |
| Timezone: | IRST |
| Utc Offset: | +3:30 |
| Timezone Dst: | IRDT |
| Utc Offset Dst: | +4:30 |
| Coordinates: | 25.5925°N 60.9003°W |
Zir Daj (Persian: زيردج, also Romanized as Zīr Daj; also known as Cher Daj, Daj, Jerdaj, and Jīrdaj) is a village in Pir Sohrab Rural District, in the Central District of Chabahar County, Sistan and Baluchestan Province, Iran. At the 2006 census, its population was 203, in 34 families.