The article presents a study on the petrogenesis and structural position of the Early Proterozoic charnockites in the Tatarnikovsky massif, located in the southern part of the Baikal uplift of the Siberian craton. The granitoids, dated at 1.85 Ga, are part of the South Siberian post-collisional magmatic belt. These charnockites form small massifs within the Davan tectonic zone but differ from the zone's rocks by lacking dynamometamorphism, mylonitization, and metasomatism, suggesting they are younger than the zone's geological structure. The granitoids coincide in time with the youngest formations in the North Baikal volcanoplutonic belt (1.85–1.84 Ga). The Tatarnikovsky granitoids exhibit two facies: coarse-grained and medium-fine-grained porphyric, with gradual transitions. Their mineral composition, including orthopyroxene, classifies them as charnockites. The chemical composition of the granitoids corresponds to monzonite and syenite, with high concentrations of Nb, Y, Zr, and Ba, and low Sr. These rocks are A-type granites with negative εNd(t) values and a model age of 2.4–2.5 Ga. The initial crystallization temperature of the granitoid melts is estimated at 890–960°C, indicating high-temperature formation. The granitoids crystallized in hypabyssal conditions at 2.2–2.9 kbar and low to moderate oxygen fugacity. The charnockites likely formed from the partial melting of mafic rocks in the lower crust, derived from differentiated tholeiitic mantle magmas. The fine-grained porphyry granitoids show fractional crystallization, while the coarse-grained ones show high Ba and Eu anomalies. The geodynamic setting is considered post-collisional extension, but local rifting occurred during the intrusion of the granitoids. The study concludes that the charnockites originated from the partial melting of mafic lower crustal rocks, with a petrogenetic model involving mantle-derived magmas. The formation of the granitoids is linked to the post-collisional extension and rifting in the region.The article presents a study on the petrogenesis and structural position of the Early Proterozoic charnockites in the Tatarnikovsky massif, located in the southern part of the Baikal uplift of the Siberian craton. The granitoids, dated at 1.85 Ga, are part of the South Siberian post-collisional magmatic belt. These charnockites form small massifs within the Davan tectonic zone but differ from the zone's rocks by lacking dynamometamorphism, mylonitization, and metasomatism, suggesting they are younger than the zone's geological structure. The granitoids coincide in time with the youngest formations in the North Baikal volcanoplutonic belt (1.85–1.84 Ga). The Tatarnikovsky granitoids exhibit two facies: coarse-grained and medium-fine-grained porphyric, with gradual transitions. Their mineral composition, including orthopyroxene, classifies them as charnockites. The chemical composition of the granitoids corresponds to monzonite and syenite, with high concentrations of Nb, Y, Zr, and Ba, and low Sr. These rocks are A-type granites with negative εNd(t) values and a model age of 2.4–2.5 Ga. The initial crystallization temperature of the granitoid melts is estimated at 890–960°C, indicating high-temperature formation. The granitoids crystallized in hypabyssal conditions at 2.2–2.9 kbar and low to moderate oxygen fugacity. The charnockites likely formed from the partial melting of mafic rocks in the lower crust, derived from differentiated tholeiitic mantle magmas. The fine-grained porphyry granitoids show fractional crystallization, while the coarse-grained ones show high Ba and Eu anomalies. The geodynamic setting is considered post-collisional extension, but local rifting occurred during the intrusion of the granitoids. The study concludes that the charnockites originated from the partial melting of mafic lower crustal rocks, with a petrogenetic model involving mantle-derived magmas. The formation of the granitoids is linked to the post-collisional extension and rifting in the region.