Mariupol is a city in Donetsk Oblast, Ukraine. It is situated on the northern coast (Pryazovia) of the Sea of Azov, at the mouth of the Kalmius River. Prior to the Russian invasion of Ukraine, it was the tenth-largest city in the country and the second-largest city in Donetsk Oblast, with an estimated population of 425,681 people in January 2022; Ukrainian authorities estimate the population of Mariupol at approximately 120,000. Mariupol has been occupied by Russian forces since May 2022.

The siege of Mariupol began on 24 February 2022 and lasted until 20 May, as part of the Russian invasion of Ukraine. It saw fighting between the Russian Armed Forces and the Ukrainian Armed Forces for control over the city of Mariupol in southeastern Ukraine. Lasting for almost three months, the siege ended in a victory for Russia and the Donetsk People's Republic, as Ukraine lost control of the city amidst Russia's eastern Ukraine offensive and southern Ukraine offensive; all Ukrainian troops remaining in the city surrendered at the Azovstal Iron and Steel Works on 20 May 2022, after they were ordered to cease fighting.