Gusinoozyorsk is a town located in the Republic of Buryatia, Russia. It serves as the administrative center of the Selenginsky District.
The town was formerly known by the name Shakhty. According to census data, its population was 24,582 in 2010, having fluctuated from 13,800 in 1970 to a peak of 29,790 during the 1989 Soviet census.