Kirensk is a town located in Russia that serves as the administrative center of the Kirensky District within Irkutsk Oblast. It is situated at the confluence of the Kirenga and Lena Rivers, approximately 950 kilometers (590 mi) north of the oblast's administrative center, Irkutsk.
According to census data, the population of the town has fluctuated over recent decades. The 2010 census recorded a population of 12,640, following a count of 13,712 in 2002 and 16,137 during the 1989 Soviet census.