| En Name: | Sayansk |
| Ru Name: | Саянск |
| Coordinates: | 54.1167°N 112°W |
| Map Label Position: | right |
| Image Coa: | Coat of Arms of Sayansk (Irkutsk oblast).png |
| Federal Subject: | Irkutsk Oblast |
| Adm Data As Of: | December 2011 |
| Adm City Jur: | Town of Sayansk |
| Adm City Jur Ref: | [1] |
| Adm Ctr Of: | Town of Sayansk |
| Inhabloc Cat: | Town |
| Mun Data As Of: | December 2011 |
| Urban Okrug Jur: | Sayansk Urban Okrug |
| Mun Admctr Of: | Sayansk Urban Okrug |
| Pop 2010Census: | 40800 |
| Established Date: | 1970 |
| Dialing Codes: | 39553 |
| Website: | http://www.admsayansk.ru/ |
| Date: | April 2010 |
Sayansk (Russian: Саянск|p=sɐˈjansk) is a town in Irkutsk Oblast, Russia, located on the Oka River (Angara River's basin) 270km (170miles) northwest of Irkutsk. Population:
Sayansk was founded in 1970. It was granted urban-type settlement status in 1975 and town status in 1985.
Within the framework of administrative divisions, it is incorporated as the Town of Sayansk[2] —an administrative unit with the status equal to that of the districts. As a municipal division, the Town of Sayansk is incorporated as Sayansk Urban Okrug.[3]