The genus Planchonia Blume is reviewed for Australia with two species recognised. Planchonia rupestris R. L. Barrett is described as a new species apparently endemic to the sandstone plateaux of the Kimberley region of Western Australia. Lectotypes are designated for Cumbia australis Britten, Planchonia crenata Miers and Planchonia arborea var. australis Benth., each of which are synonyms of Planchonia careya (F.Muell.) Kunth. Illustrations, distribution maps and a key to the Australian species are presented.