Mariupol is a city in Donetsk Oblast, Ukraine. It is situated on the northern coast 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; as of August 2023, Ukrainian authorities estimate the population of Mariupol at approximately 120,000.