Dian Fossey, American zoologist and anthropologist (d. 1985)
Dian Fossey (, January 16, 1932 – c. December 26, 1985) was an American primatologist and conservationist known for undertaking an extensive study of mountain gorilla groups from 1966 until her murder in 1985. She studied them daily in the mountain forests of Rwanda, initially encouraged to work there by paleoanthropologist Louis Leakey. Gorillas in the Mist, a book published two years before her death, is Fossey's account of her scientific study of the gorillas at Karisoke Research Center and prior career. It was adapted into a 1988 film of the same name.Fossey was a leading primatologist, and a member of the "Trimates", a group of female scientists recruited by Leakey to study great apes in their natural environments, along with Jane Goodall who studies chimpanzees, and Biruté Galdikas, who studies orangutans.Fossey spent 20 years in Rwanda, where she supported conservation efforts, strongly opposed poaching and tourism in wildlife habitats, and made more people acknowledge the sapience of gorillas. Following the killing of a gorilla and subsequent tensions, she was murdered in her cabin at a remote camp in Rwanda in December 1985. Although Fossey's American research assistant was convicted in absentia, there is no consensus as to who killed her.

Her research and conservation work helped reduce the downward population trend in mountain gorillas.