Papilio ambrax, the Ambrax butterfly, is a butterfly of the family Papilionidae. It is found in Queensland, Australia, as well as the Aru Islands, Papua (Indonesia), and Papua New Guinea. The wingspan is 90–100 mm. The larvae feed on Citrus species, Clausena brevistyla, Limonia acidissima, Microcitrus garrawayae, Microcitrus inodora, Murraya koenigii, Zanthoxylum ailanthoides, Zanthoxylum brachyacanthum, Zanthoxylum nitidum, Zanthoxylum ovalifolium, and Morinda citrifolia.