We examined differences in morphology and advertisement calls of a large sample of frogs from the Australo-Papuan Region that resemble Litoria bicolor, and compared them with examples of that species from Australia. Consistent differences in body size, body proportions, and advertisement call structure among populations demonstrate that at least seven distinct species occur in the Australo-Papuan region, and that only the population represented by the holotype from the Northern Territory of Australia is Litoria bicolor s. s. Herein we describe four new species from the Papuan Region and comment on the origin and evolution of the Papuan members of the Litoria bicolor complex in the region.