| Official Name: | Bostaq |
| Native Name: | بسطاق |
| Settlement Type: | village |
| Pushpin Map: | Iran |
| Mapsize: | 150px |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Name1: | South Khorasan |
| Subdivision Type2: | County |
| Subdivision Name2: | Sarayan |
| Subdivision Type3: | Bakhsh |
| Subdivision Name3: | Seh Qaleh |
| Subdivision Type4: | Rural District |
| Subdivision Name4: | Seh Qaleh |
| Population As Of: | 2006 |
| Population Total: | 1,136 |
| Population Density Km2: | auto |
| Timezone: | IRST |
| Utc Offset: | +3:30 |
| Timezone Dst: | IRDT |
| Utc Offset Dst: | +4:30 |
| Coordinates: | 33.7533°N 58.5397°W |
Bostaq (Persian: بسطاق, also Romanized as Bosţāq, Basţāq, and Bustāq) is a village in Seh Qaleh Rural District, Seh Qaleh District, Sarayan County, South Khorasan Province, Iran. At the 2006 census, its population was 1,136, in 236 families.