Baikal Cossacks were Cossacks of the Transbaikal Cossack Host (), a Cossack host formed in 1851 in the areas beyond Lake Baikal (hence, Transbaikal). The Transbaikal Cossack Host partially consisted of Siberian Cossaks, Buryats, Evenk (Tungus) military units, and peasant population of some of the regions. The army included three cavalry regiments and three unmounted brigades. Its main purpose was to patrol the Sino-Russian border and perform everyday military duties. Nakazny ataman (the one who was appointed) was in charge of the Transbaikal Cossack Army. He would also serve as a military governor of the Transbaikal oblast with its headquarters in Chita, starting from 1872.