The article presents data on the new locations of two rare plant species, Galium odoratum (L.) Scop. and G. paradoxum Maxim., in the Baikalsky Nature Reserve and its buffer zone. The eastern distribution limits of both species in the Siberian part of their disjunctive ranges are clarified. The species habitats in the found localities are characterized, and the area and local population sizes are estimated. Galium odoratum is a new addition to the flora of the Republic of Buryatia, G. paradoxum is found to be more widespread here than previously thought. The history of records of both species in the Baikal region is addressed, considering previously erroneous and revised identification of herbarium specimens, as well as supposedly lost and newly found localities. The question of the relict pattern of G. odoratum and G. paradoxum distribution on the northern macroslope of the Khamar-Daban Ridge is discussed. Galium odoratum is proposed for inclusion into the Red Data Book of the Republic of Buryatia. The types of habitats that are most promising for the search for new localities of G. odoratum and G. paradoxum in the Southern Baikal region are indicated.