| Official Name: | Chayan |
| Native Name: | چايان |
| Settlement Type: | village |
| Pushpin Map: | Iran |
| Mapsize: | 150px |
| Subdivision Type: | Country |
| Subdivision Type1: | Province |
| Subdivision Name1: | Hamadan |
| Subdivision Type2: | County |
| Subdivision Name2: | Bahar |
| Subdivision Type3: | Bakhsh |
| Subdivision Name3: | Central |
| Subdivision Type4: | Rural District |
| Subdivision Name4: | Simineh Rud |
| Population As Of: | 2006 |
| Population Total: | 145 |
| Population Density Km2: | auto |
| Timezone: | IRST |
| Utc Offset: | +3:30 |
| Timezone Dst: | IRDT |
| Utc Offset Dst: | +4:30 |
| Coordinates: | 34.8592°N 48.4014°W |
Chayan (Persian: چايان, also Romanized as Chāyān) is a village in Simineh Rud Rural District, in the Central District of Bahar County, Hamadan Province, Iran. At the 2006 census, its population was estimated at 145, in 75 families.