| En Name: | Udarnik |
| Ru Name: | Ударник |
| Coordinates: | 62.9303°N 134.4653°W |
| Map Label Position: | right |
| Federal Subject: | Sakha Republic |
| Adm District Jur: | Tomponsky District |
| Adm Selsoviet Jur: | Bayagantaysky Rural Okrug |
| Adm Selsoviet Type: | Rural okrug |
| Inhabloc Cat: | Rural locality |
| Inhabloc Type: | Selo |
| Mun District Jur: | Tomponsky Municipal District |
| Mun District Jur Ref: | [1] |
| Rural Settlement Jur: | Bayagantaysky Rural Settlement |
| Pop Latest: | 159 |
| Pop Latest Date: | 2002 |
| Postal Codes: | 678724 |
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 115km (71miles) from Khandyga, the administrative center of the district and 25km (16miles) from Krest-Kaldzhan. Its population as of the 2002 Census was 159.[2] It is named after the Russian word for a hard worker.