Sievierodonetsk (ˌsɛvərədɒˈnjɛtsk ; Сєвєродонецьк, ˌsjɛwjerodoˈnɛtsjk), also spelled Severodonetsk (Северодонецк), is a city in Luhansk Oblast, eastern Ukraine. It is located to the northeast of the left bank of the Donets river and approximately to the northwest from the administrative center of the oblast, Luhansk. Sievierodonetsk faces neighbouring Lysychansk across the river. The city, whose name comes from the above-mentioned river, had a population of making it then the second-most populous city in the oblast. Since June 2022, it has been militarily occupied and administered by Russia.
Prior to the war, Sievierodonetsk had several factories as well as the Azot chemical plant. There was also an airport to the south of the city.
Sievierodonetsk served as the administrative centre of Luhansk Oblast from 2014 to 2022, due to the city of Luhansk falling under the control of pro-Russian separatists at the start of the war in Donbas. During the Russian invasion of Ukraine, Sievierodonetsk came under heavy attack from Russian forces and was the forefront of the battle of Donbas, resulting in extensive destruction to the city, including residential areas. By 25 June 2022, the city was fully captured by Russian and separatist forces, with Ukrainian authorities claiming that the civilian population was approximately 10,000, or ten percent of its pre-war population.
According to one of the versions, the city got its name from the Donets. Had a Russian name on it, (Сѣверный Донецъ, (): Северский Донець) the name of the city in Russian is Severodonetsk. In another account, the name comes from the location of the city, which is situated to the north of the Donets bank.
The Ukrainian name of the city has a rather complicated history. The decree of the Presidium of the Supreme Soviet of the Ukrainian Soviet Socialist Republic dated 27 January 1950, "On the renaming of the urban-type settlement Lyskhimstroi of the Lysychansk Raion of the Voroshilovgrad Oblast" was issued in Russian, and the name of the city was indicated as Severodonetsk, which was later translated into Ukrainian as Sievierodonetsk.