Zelenogorsk () is a closed town in Krasnoyarsk Krai, Russia, located on the left bank of the Kan River above its confluence with the Yenisei River. It was formerly known as Krasnoyarsk-45 () and was involved in enriching uranium for the Soviet nuclear program. Population:
It was granted town status in 1956.
As a closed town, it went under the code-name Krasnoyarsk-45 until Russian president Boris Yeltsin decreed, in 1992, that such cities could use their historical names. The town appeared on no official maps until then. As is the tradition with Soviet towns containing secret facilities, the designation "Krasnoyarsk-45" is actually a postcode; it implied that the place was located directly in the city of Krasnoyarsk, but really from it. The city still remains closed, by a vote of the inhabitants. Access is possible only by having a special entry permit issued by the city's authorities.
Within the framework of administrative divisions, it is incorporated as the closed administrative-territorial formation of ZelenogorskâÂÂan administrative unit with the status equal to that of the districts. As a municipal division, the closed administrative-territorial formation of Zelenogorsk is incorporated as Zelenogorsk Urban Okrug.
It is a sister city with Newburyport, Massachusetts, United States.