We present the best sampled phylogenetic analysis of Celastrales, with respect to both character and taxon sampling, and use it to present a natural classification of the order. Parnassiaceae are highly supported as sister to Celastraceae; we recognize both families as distinct. Pottingeria is highly supported as a member of Celastraceae. We recognize and circumscribe 13 subfamilies in Celastraceae, including the new subfamilies Crossopetaloideae, Maytenoideae, Microtropioideae, Monimopetaloideae, and Salaciopsioideae. We identified five genera that likely require generic recircumscriptions: Cassine, Elachyptera, Gymnosporia, Salacia, and Semialarium. Genera that had not been previously sampled in Sanger-sequence-based studies are resolved as follows: Arnicratea is sister to Reissantia, Bequaertia is in a clade with Campylostemon and Tristemonanthus, Goniodiscus is sister to Wilczekra, Ptelidium is nested within Elaeodendron, and Tetrasiphon is most closely related to Gyminda.