Genyornis newtoni is an extinct species of large, flightless bird that lived in Australia during the Pleistocene Epoch until around 50,000 years ago.

The species was first described in 1896 by Edward Charles Stirling and A. H. C. Zeitz, the authors giving the epithet newtoni for the Cambridge professor Alfred Newton.

The name of the genus is derived from the ancient Greek γένυς (génus) 'jaw; chin' and ὄρνις (órnis) 'bird', because of the relatively large size of the lower mandible.

The paper reviewed previously described fossil remains of "struthious [ostrich-like] birds in Australia", which had either been assigned to the ancient emus of Dromaius or the only described species of Dromornis, D. australis Owen.

[3] Prior to 2024, reconstructions of the skull of Genyornis were primarily based on those of its closest relatives, due to the heavily damaged nature of the holotype.

The authors considered this to be a very good indication that the entire mass extinction event in Australia was due to human activity, rather than climate change.

The birds recovered from the site seemed to have been particularly prone to osteomyelitis, as a result of getting stuck in the mud of the drying lake bed as the water receded.

[21] A 2024 study of the skull morphology of Genyornis found apparent adaptations to feeding on aquatic plants, making them closely tied to freshwater habitats.

A reliance on these habitats may have made the species uniquely vulnerable to the loss of freshwater lakes during the aridification of Australia during the late Pleistocene, potentially leading to its extinction.