A new species of Sphinctanthus from the Rio Doce Valley, Atlantic forest in the state of Minas Gerais, Brazil, is here described and illustrated. The species is peculiar within the genus by having placentation entirely parietal, while in the other species of Sphinctanthus the placentation is basally axial and distally parietal. In addition, despite its bright orange flowers (being a plant with high potential as an ornamental), it is only known from two collections from nearby localities, indicating that it is a rare and critically endangered species.