Lensk (Russian: Ленск, IPA: [lʲɛnsk]; Yakut: Лиэнскэй, Lienskey) is a town and the administrative center of Lensky District of the Sakha Republic, Russia.

It experienced a period of rapid growth during the 20th century as a result of the discovery and development of diamond deposits in the Vilyuy River basin.

[citation needed] In May 2001, Lensk briefly came to the world's attention when almost the entire town was flooded and a large amount of the buildings destroyed.

[3] In addition to its association with the diamond industry and construction, Lensk has a significant forestry and timber sector and a large-panel housing factory.

As a major port on the Lena, the town has developed as a processing point for the regional diamond industry.