Udarnik (Russian: Ударник) is a rural locality (a selo), and one of three settlements in Bayagantaysky Rural Okrug of Tomponsky District in the Sakha Republic, Russia, in addition to Krest-Khaldzhan, the administrative center of the Rural Okrug and Ary-Tolon.

It is located 115 kilometers (71 mi) from Khandyga, the administrative center of the district and 25 kilometers (16 mi) from Krest-Kaldzhan.

Its population as of the 2002 Census was 159.

[1] It is named after the Russian word for a hard worker.

This Sakha Republic location article is a stub.