Olenya Bay or Olenya Guba is a bay of the Barents Sea on the Kola Peninsula in the Murmansk Oblast, Russia. It is an extension of the Kola Inlet, which opens out to the north into the Barents Sea. The Pechenga River discharges into the bay.

GUGI: 29th submarine division Military Unit 13090

A Russian naval, formerly Soviet, base is located on the shores of the bay. The base supports GUGI (, transcribed as Glavnoye upravlenie glubokovodnikh issledovanii or GUGI) with its objective to operate submarines that are able to dive deep into the sea, in order to gather intelligence or to work with installations on the seabed, including sabotage. It is part of the naval installation at Gadzhievo (also known as Skalisty) in the Murmansk Oblast, and is home port to submarine units of Russia's Northern Fleet including the 29th submarine division Military Unit 13090 which was known as the 29th special purpose submarine brigade from 1979 until January 2018. The Russian vessel Yantar is often seen moored at Olenya Bay. According to a 2008 article in Kommersant, the 29th special purpose submarine brigade included:

Belgorod

In July 2022, the Belgorad, which is a sister ship of the Kursk that was home ported at Vidyayevo, joined the 29th submarine division.

GUGI reactors

Okolnaya Bay is the location of undersea GUGI reactors. Near Severomorsk according to a Barents Observer article, support for nuclear weapons handling which possibly could be used for Poseidon drones deployed in the Barents Arctic region are located at Okolnaya Bay as well. According to a November 2016 Izvestia article, Okolnaya supports "Harmony-S" for the system index "Harmony-NZ" which uses robotic autonomous bottom stations (ABS) that are covertly installed on the seabed by special submarines.

Hvaldimir

In May 2019 satellite views of the base taken from Google maps were republished noting pens that suggested military use of cetaceans at Olenya Bay, including possibly a tame beluga whale discovered in Northern Norway what has been dubbed Hvaldimir.