| Official Name: | Siah Kalan |
| Native Name: | سياه كلان |
| Settlement Type: | village |
| Pushpin Map: | Iran |
| Mapsize: | 150px |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Name1: | Alborz |
| Subdivision Type2: | County |
| Subdivision Name2: | Karaj |
| Subdivision Type3: | Bakhsh |
| Subdivision Name3: | Central |
| Subdivision Type4: | Rural District |
| Subdivision Name4: | Kamalabad |
| Population As Of: | 2006 |
| Population Total: | 712 |
| Population Density Km2: | auto |
| Timezone: | IRST |
| Utc Offset: | +3:30 |
| Coordinates: | 35.8883°N 51.0058°W |
Siah Kalan (Persian: سياه كلان, also Romanized as Sīāh Kalān; also known as Sīāh Kolāhān) is a village in Kamalabad Rural District, in the Central District of Karaj County, Alborz Province, Iran. At the 2006 census, its population was 712, in 204 families.