Ust-Omchug (Russian: Усть-Омчуг) is an urban locality (an urban-type settlement) and the administrative center of Tenkinsky District of Magadan Oblast, Russia, located at the 271-kilometer (168 mi) mark of the highway to the northwest of Magadan.

The settlements were part of the Soviet correctional system of GULAG.

There is an ore-mining and processing plant, a mining equipment repair shop, a timber industry company, and a poultry farming sovkhoz.

Winters are prolonged and very cold, with up to eight months of sub-zero maximum daily temperatures, such that the soil remains permanently frozen.

Average temperatures range from −32.6 °C (−26.7 °F) in January to +12.7 °C (54.9 °F) in July.