Alazeya River (Russian: Алазея) is a river in the northeastern part of Yakutia, Russia. The length of the river is 1,590 km. The area of its basin is 64,700 sq km. The Alazeya is formed by the confluence of the Nelkan and Kadylchan Rivers and drains into the East Siberian Sea. There are more than 24,000 lakes in the basin of the Alazeya River. It freezes up in late September - early October and stays icebound until late May - early June. The biggest tributary of the Alazeya is the Rossokha River.