The South Island takahē (Porphyrio hochstetteri) is a flightless swamphen indigenous to New Zealand and the largest living member of the rail family. It is often known by the abbreviated name takahē, which it shares with the recently extinct North Island takahē. The two takahē species are also known as notornis.

Takahē were hunted extensively by Māori but was not named and described by Europeans until 1847, and then only from fossil bones. In 1850 a living bird was captured, and three more collected in the 19th century. After another bird was captured in 1898, and no more were to be found, the species was presumed extinct. Fifty years later, however, after a carefully planned search, South Island takahē were dramatically rediscovered in 1948 by Geoffrey Orbell in an isolated valley in the South Island's Murchison Mountains. The species is now managed by the New Zealand Department of Conservation, whose Takahē Recovery Programme maintains populations on several offshore islands as well as Takahē Valley. It has now been reintroduced to a second mainland site in Kahurangi National Park. Although South Island takahē are still a threatened species, their NZTCS status was downgraded in 2016 from Nationally Critical to Nationally Vulnerable. The population is 440 (as of October 2021) and is growing by 10 percent per year.