The amphibians of Australia are restricted to those of the order Anura (frogs and toads). The taxonomy of Australian frogs is disputed in accordance to the number of families; there is currently a maximum of six families of native frog, and one introduced toad, the Cane Toad. In 1935, the Cane Toad was introduced to Australia in a failed attempt to control pests in sugarcane crops. It has since become a devastating pest, spreading across northern Australia. As well as competing with native insectivores for food, the Cane Toad produces a venom that is toxic to native fauna and humans.
The Australian froglets, of the family Myobatrachidae, comprise 11 genera. They are small ground-dwelling frogs, typically of dull colour. Notable members of this group is the colourful and endangered corroboree frogs, which are the only frog species in the world known to produce their own poison. Most poisonous frogs will derive their poison from their diet. The frogs of the family Limnodynastidae, which contains eight genera, are ground-dwelling frogs of medium to large size. Many of the species within the genus Limnodynastes are commonly called "Pobblebonks"—for example, the Eastern Pobblebonk—after their distinctive "bonk" call. The gastric-brooding frogs, of the family Rheobatrachidae, comprise only two species from one genus. These species are unique in the animal kingdom for their ability to raise their young in their stomach. They were originally distributed in small, isolated areas in Queensland, and are now thought to be extinct. The tree frogs, from family Hylidae, are common in high-rainfall areas on the northern and eastern coasts, although they are present throughout the continent; there are 77 Australian species from three genera. White's Tree Frog, from this family, is one of the most popular pet frogs throughout the world, mainly due to its docile nature. The 18 species from two genera of the Microhylidae frogs are restricted to the rainforests; the smallest species, the Scanty Frog, is from this family. There is a single species from the world's dominant frog group, family Ranidae—the Australian Wood Frog—which occurs only in the Queensland rainforests.
As elsewhere, there has been a precipitous decline in Australia's frog populations in recent years. Although the full reasons for the decline are uncertain, it can be at least partly attributed to the fatal amphibian fungal disease chytridiomycosis.