Kupiansk or Kupyansk (Ukrainian: Куп'янськ, IPA: [ˈkupjɐnʲsʲk]; Russian: Купянск, IPA: [ˈkupʲɪnsk]) is a city in Kharkiv Oblast, Ukraine. It serves as the administrative center of Kupiansk Raion. It is also an important railroad junction for the oblast. Kupiansk hosts the administration of Kupiansk urban hromada, one of the hromadas of Ukraine. It had a population of 26,627 (2022 estimate). In February 2024, more than 3,500 people remained in the city. As of November 2025, Russian forces claim control of the city while top Ukrainian military officials deny this.
Until 18 July 2020, Kupiansk was incorporated as a city of oblast significance and the center of Kupiansk Municipality. The municipality was abolished in July 2020, as part of administrative reforms in Ukraine, which reduced the number of raions in Kharkiv Oblast to seven. The area of Kupiansk Municipality was merged into Kupiansk Raion.