| Official Name: | Zeydar |
| Native Name: | زيدر |
| Settlement Type: | village |
| Pushpin Map: | Iran |
| Mapsize: | 150px |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Name1: | South Khorasan |
| Subdivision Type2: | County |
| Subdivision Name2: | Sarbisheh |
| Subdivision Type3: | Bakhsh |
| Subdivision Name3: | Mud |
| Subdivision Type4: | Rural District |
| Subdivision Name4: | Naharjan |
| Population As Of: | 2006 |
| Population Total: | 373 |
| Population Density Km2: | auto |
| Timezone: | IRST |
| Utc Offset: | +3:30 |
| Timezone Dst: | IRDT |
| Utc Offset Dst: | +4:30 |
| Coordinates: | 32.3139°N 59.4717°W |
Zeydar (Persian: زيدر, also Romanized as Zaidar; also known as Zainalābād and Zeynalābād) is a village in Naharjan Rural District, Mud District, Sarbisheh County, South Khorasan Province, Iran. At the 2006 census, its population was 373, in 90 families.