| Official Name: | Sian-e Sofla |
| Native Name: | سيان سفلي |
| Settlement Type: | village |
| Pushpin Map: | Iran |
| Mapsize: | 150px |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Name1: | Markazi |
| Subdivision Type2: | County |
| Subdivision Name2: | Khomeyn |
| Subdivision Type3: | Bakhsh |
| Subdivision Name3: | Central |
| Subdivision Type4: | Rural District |
| Subdivision Name4: | Hamzehlu |
| Population As Of: | 2006 |
| Population Total: | 422 |
| Population Density Km2: | auto |
| Timezone: | IRST |
| Utc Offset: | +3:30 |
| Timezone Dst: | IRDT |
| Utc Offset Dst: | +4:30 |
| Coordinates: | 33.8253°N 50.0589°W |
Sian-e Sofla (Persian: سيان سفلي, also Romanized as Sīān-e Soflá, Seyān Soflá, and Siyan Sofla; also known as Sīān-e Pā’īn and Siān Pāīn) is a village in Hamzehlu Rural District, in the Central District of Khomeyn County, Markazi Province, Iran. At the 2006 census, its population was 422, in 117 families.