Barguzinsky Nature Reserve () is the oldest of zapovedniks (nature reserves). It is located in Buryatia (Russia) on the west slope of the Barguzin Range, including the northeast shores of the Lake Baikal and a part of the lake itself. The name of the preserve (and the range) comes from the Barguzin River. The area of the reserve is . It was created in 1916 to preserve and increase the numbers of Barguzin Sable (Martes zibellina). Mountainous and taiga landscapes are also being preserved.