We provide a taxonomic diagnosis and discussion of the frogs of the Rana papua group within Milne Bay Province, the southeasternmost extent of New Guinea and associated offshore islands. Six members of the R. papua species group occur in the province. We rediagnose R. grisea, known with certainty only from the type locality in Papua Province, Indonesia, and note that most, if not all, specimens referred to this species in New Guinea are mis-assigned. We rediagnose R. supragrisea and note that the type series contains members of at least two or three different morphospecies. The true geographical limits of this species outside of southeastern New Guinea and associated islands remain to be determined. We resurrect R. milneana from the synonymy of R. daemeli and note its close relationships to two species recently described from far western New Guinea. We describe one new species closely related to R. daemeli and occurring on the mainland portion of the province and in the D'Entrecasteaux Islands. We describe the tadpoles of two of these species for the first time. As previously noted, members of the R. papua species complex are difficult to distinguish using traditional morphological measurements but call and (sometimes) habitat are important for this purpose. Contrary to previous researchers, we have found color pattern to be valuable for distinguishing among Rana species within the limited confines of Milne Bay Province and anticipate that it will prove equally useful in diagnosing other geographically constrained Rana faunas throughout New Guinea.