Nambaroo bullockensis sp. nov. is a structurally primitive macropodoid from the Bullock Creek Local Fauna of the Camfield Beds of the Northern Territory, Australia. This species extends the range of Nambaroo from the late Oligocene or early Miocene up to the middle Miocene. Despite its young age, N. bullockensis retains many features thought to be plesiomorphic for macropodoids. Cladistic analysis based on characters of m1 for this new species and all other balbarines shows Nambaroo to be paraphyletic, but supports the monophyly of Ganawamaya and Balbaroo.