Zaozyorsk (Russian: Заозёрск), formerly known as Zaozyorny (Заозёрный), Severomorsk-7 (Североморск-7), and Murmansk-150 (Му́рманск-150), is a closed town in Murmansk Oblast, Russia.

[8] Building of what was to become Zaozyorsk began in 1958 as a base for a nuclear underwater fleet that would be deployed in 1961.

[2] Originally known as Zaozyorny (Заозёрный), it was referred to as Severomorsk-7 (Североморск-7) for postal purposes.

[2] On September 14, 1981, it was granted town status and renamed Zaozyorsk, although for postal purposes the name Murmansk-150 (Му́рманск-150) was used.

[2] Within the framework of administrative divisions, it is incorporated as the closed administrative-territorial formation of Zaozyorsk—an administrative unit with the status equal to that of the districts.