| Official Name: | Sereyn |
| Native Name: | سرئين |
| Settlement Type: | village |
| Pushpin Map: | Iran |
| Mapsize: | 150px |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Name1: | Zanjan |
| Subdivision Type2: | County |
| Subdivision Name2: | Khodabandeh |
| Subdivision Type3: | Bakhsh |
| Subdivision Name3: | Bizineh Rud |
| Subdivision Type4: | Rural District |
| Subdivision Name4: | Zarrineh Rud |
| Population As Of: | 2006 |
| Population Total: | 447 |
| Population Density Km2: | auto |
| Timezone: | IRST |
| Utc Offset: | +3:30 |
| Timezone Dst: | IRDT |
| Utc Offset Dst: | +4:30 |
| Coordinates: | 35.7367°N 48.5233°W |
Sereyn (Persian: سرئين, also Romanized as Sareyen, Sarīn, and Serīn; also known as Sūzīn) is a village in Zarrineh Rud Rural District, Bizineh Rud District, Khodabandeh County, Zanjan Province, Iran. At the 2006 census, its population was 447, in 79 families.