A new species in the Old World genus Debregeasia (Urticaceae), D. australis Friis, Wilmot-Dear & C.J.Chen, based on material from forest habitats in eastern Queensland, Australia, is described, illustrated and mapped. A new synopsis of the genus and a new key to species recognised is provided as a supplement to the revision of Debregeasia by C. M. Wilmot-Dear in 1988. Debregeasia orientalis, described from China since 1988, is accepted, species from China and Bangladesh (D. elliptica and D. dentata) are reinstated, and other taxonomic changes made since the revision of 1988 are summarised.
