Sast
| Sast Persian: سست | |
|---|---|
| Village | |
| Coordinates: 37°08′07″N 57°32′03″E / 37.13528°N 57.53417°E | |
| Country | Iran | 
| Province | North Khorasan | 
| County | Esfarayen | 
| District | Central | 
| Rural District | Ruin | 
| Population  (2016) | |
|  • Total | 2,540 | 
| Time zone | UTC+3:30 (IRST) | 
Sast (Persian: سست) is a village in Ruin Rural District of the Central District of Esfarayen County, North Khorasan province, Iran.