Cassowaries, genus Casuarius, are ratites (flightless birds without a keel on their sternum bone) that are native to the tropical forests of New Guinea (Papua New Guinea and Indonesia), nearby islands, and northeastern Australia.

The most common of these, the southern cassowary, is the third-tallest and second-heaviest living bird, smaller only than the ostrich and emu.

Cassowaries feed mainly on fruit, although all species are truly omnivorous and will take a range of other plant food, including shoots and grass seeds, in addition to fungi, invertebrates, and small vertebrates. Cassowaries are very shy, but when provoked they are capable of inflicting injuries, occasionally fatal, to dogs and people.