The Kolyma River (Russian: Колыма́; IPA: [kəlɨˈma]) is a river in northeastern Siberia, whose basin covers parts of the Sakha Republic, Chukotka Autonomous Okrug, and Magadan Oblast of Russia. It rises in the mountains north of Okhotsk and Magadan, in the area of and empties into the Kolyma Gulf (Kolymskiy Zaliv) of the East Siberian Sea, a division of the Arctic Ocean, at . The Kolyma is 2,129 kilometres (1,323 mi) long. The area of its basin is 644,000 km².
The Kolyma is frozen to depths of several metres for about 250 days each year, becoming free of ice only in early June, until October.
In 1640 Dimitry Zyryan (also called Yarilo or Yerilo) went overland to the Indigirka. In 1641 he sailed down the Indigirka, went east and up the Alazeya. Here they heard of the Kolyma and met Chukchis for the first time. In 1643 he returned to the Indigirka, sent his yasak to Yakutsk and went back to the Alazeya. In 1645 he returned to the Lena where he met a party and learned that he had been appointed prekazshchik of the Kolyma. He returned east and died in early 1646. In the winter of 1641-42 Mikhail Stadukhin, accompanied by Semyon Dezhnyov, went overland to the upper Indigirka. He spent the next winter there, built boats and sailed down the Indigirka and east to the Alazeya where he met Zyryan. Zyrian and Dezhnev stayed at the Alazeya, while Stadukhin went east, reaching the Kolyma in the summer of 1644. They built a zimovye, probably at Srednekolymsk and returned to Yakutsk in late 1645.
In 1892-1894 Baron Eduard Von Toll carried out geological surveys in the basin of the Kolyma (among other Far-eastern Siberian rivers) on behalf of the Russian Academy of Sciences (Barr, 1980). During one year and two days the expedition covered 25,000 km, of which 4,200 km were up rivers, carrying out geodesic surveys en route.
The Kolyma is known for its Gulag labour camps and gold mining, both of which have been extensively documented since Joseph Stalin era Soviet archives opened. The river gives its title to a famous anthology about life in Gulag camps by Varlam Shalamov, The Kolyma Tales.