Carl Hunstein (1843 — March 13, 1888) was a German administrator, ornithologist and plant collector.
Hunstein was born in Homberg/Efze, Germany. He emigrated to America and from 1885 until his death was employed by the German New Guinea Company.
He was the most successful discoverer of new species of birds of paradise by discovering Brown Sicklebill, Stephanie's Astrapia, Blue Bird of Paradise and Emperor Bird of Paradise.
Hunstein lost his life when a tsunami, caused by the Ritter Island volcano, hit the coast of New Britain of Bismarck Archipelago.
He is commemorated in New Guinea by the Hunstein Mountains and the Hunstein Forest, and in plants and animals including the Mottled Munia Lonchura hunsteini and Cyathea hunsteiniana.