The fossil carnivore fauna of the late Eocene (Bridgerian-Uintan) and early Oligocene (Chadronian) of Trans-Pecos Texas includes specimens from stratigraphically superimposed faunas of three areas: the Sierra Vieja (Vieja Group), the badlands near Agua Fria Mountain (Buck Hill Group), and near Castolon in southern Big Bend National Park (Chisos Formation). Members of the mammalian orders Condylarthra, Creodonta, and Carnivora are included in this study. The fossils occur in volcaniclastic continental sediments, interbedded with lava flows and ignimbrites. The Cenozoic rocks unconformably overlie Cretaceous sedimentary rocks in all three areas. Radiometric dates from several stratigraphic levels allow the calibration of biostratigraphic data.