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The Sawahlunto Formation is a coal-rich geological formation in the Ombilin Basin, located in central Sumatera. It contains three main coal seams, designated as Seams A, B, and C, with Seam C known for its high-quality coal. The study involved analyzing coal samples from Seam C using petrographic and proximate analysis methods. Petrographic analysis assessed the macroscopic composition and vitrinite reflectance, which are essential for determining the depositional environment and coal rating. Proximate analysis provided additional data necessary for evaluating the coal’s quality. The coal was predominantly composed of vitrinite (79.2%-80.6%) and inertinite (19.2%-20.8%). Plots of the Tissue Preservation Index (TPI) and Gelification Index (GI) indicated a limno-telmatic depositional environment. Vitrinite reflectance ranged from 0.45%-0.51%, classifying the coal as sub-bituminous. The calorific values were 15,117.2 btu/lb and 14,815.94 btu/lb, categorizing the coal as highly volatile bituminous.