| Official Name: | Siyun Sar |
| Native Name: | سئون سر |
| Settlement Type: | village |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Name1: | Gilan |
| Subdivision Type2: | County |
| Subdivision Name2: | Talesh |
| Subdivision Type3: | Bakhsh |
| Subdivision Name3: | Central |
| Subdivision Type4: | Rural District |
| Subdivision Name4: | Tula Rud |
| Population As Of: | 2006 |
| Population Total: | 37 |
| Population Density Km2: | auto |
| Timezone: | IRST |
| Utc Offset: | +3:30 |
| Timezone Dst: | IRDT |
| Utc Offset Dst: | +4:30 |
Siyun Sar (Persian: سئون سر, also Romanized as Si’yūn Sar) is a village in Tula Rud Rural District, in the Central District of Talesh County, Gilan Province, Iran. At the 2006 census, its population was 37, in 9 families.