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Polyarny District (Russian: Поля́рный райо́н) was an administrative division (a district) of Murmansk Okrug of Leningrad Oblast of the Russian SFSR, Soviet Union, and later of Murmansk Oblast, which existed in 1927–1960.
It was established as Alexandrovsky District on August 1, 1927, when the All-Russian Central Executive Committee (VTsIK) issued two Resolutions: "On the Establishment of Leningrad Oblast" and "On the Borders and Composition of the Okrugs of Leningrad Oblast". According to these resolutions, Murmansk Governorate was transformed into Murmansk Okrug, which was divided into six districts (Alexandrovsky being one of them) and included into Leningrad Oblast. The administrative center of the district was in the selo of Alexandrovskoye (Polyarnoye), and later in Murmansk. Upon establishment, Alexandrovsky/Polyarny, Belokamensky, Gryazno-Gubsky, Toros-Ostrovsky, Tyuva-Gubsky, and Ura-Gubsky Selsoviets of the former Alexandrovskaya Volost were included into the district.
On July 31, 1930, the administrative commission of the Leningrad Executive Committee granted the district the status of an ethnic Finnish district. The Presidium of the Leningrad Oblast Executive Committee confirmed this decision on January 7, 1931.
On November 20, 1930, the Presidium of the VTsIK issued a resolution prescribing to rename those districts of the Russian SFSR which share a name with another district. Consequently, in December 1930, Leningrad Oblast Executive Committee asked the Alexandrovsky District Executive Committee to come up with a new name for the district; one which would be representative of local geographical and ethnic conditions. On January 12, 1931, the Third Congress of the Soviets of Alexandrovsky District issued a resolution, renaming the district "Polyarny"; the village of Alexandrovskoye was renamed Polyarnoye.] The new name, which literally means "polar", was explained by the fact that of all the districts of Leningrad Oblast, Polyarny is the closest to the North Pole and experiences polar nights in winter. On March 5, 1931 the new name was approved by the administrative commission of the Leningrad Oblast Executive Committee, and on March 11, 1931—by its Presidium.
The inhabited locality of Abram-Mys was transferred from Polyarny District to the administrative jurisdiction of Murmansk City Soviet by the Decree of the Presidium of the Supreme Soviet of the Russian SFSR of January 3, 1950.
On April 18, 1951, the work settlement of Vayenga was elevated in status to that of a town under oblast jurisdiction and renamed Severomorsk. On April 26, 1951, by the Decision of Murmansk Oblast Executive Committee, several inhabited localities of Polyarny District were passed into its jurisdiction.
By the June 14, 1956 Decree of the Presidium of the Supreme Soviet of the RSFSR, the town of Polyarny was demoted in status to that of a town under district jurisdiction and subordinated to Polyarny District.
The district was abolished by the Decree of the Presidium of the Supreme Soviet of the RSFSR of July 9, 1960. The district's territory was divided between Kolsky, Pechengsky, and Teribersky Districts, with the town of Polyarny being administratively subordinated to the town of Severomorsk.