| Official Name: | Hesar-e Seyyedlar |
| Native Name: | حصارسيدلر |
| Settlement Type: | village |
| Pushpin Map: | Iran |
| Mapsize: | 150px |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Name1: | East Azerbaijan |
| Subdivision Type2: | County |
| Subdivision Name2: | Ahar |
| Subdivision Type3: | Bakhsh |
| Subdivision Name3: | Central |
| Subdivision Type4: | Rural District |
| Subdivision Name4: | Qeshlaq |
| Population As Of: | 2006 |
| Population Total: | 34 |
| Population Density Km2: | auto |
| Timezone: | IRST |
| Utc Offset: | +3:30 |
| Timezone Dst: | IRDT |
| Utc Offset Dst: | +4:30 |
| Coordinates: | 38.39°N 47.2719°W |
Hesar-e Seyyedlar (Persian: حصارسيدلر, also Romanized as Ḩeşār-e Seyyedlar; also known as Ḩeşār) is a village in Qeshlaq Rural District, in the Central District of Ahar County, East Azerbaijan Province, Iran. At the 2006 census, its population was 34, in 10 families.