Richard Leakey was born at Nairobi in Kenya, the son of the famous scholars Louis and Mary Leakey. Having left school at sixteen, he first worked as a hunter and animal collector before turning in 1964 to the search for fossil humans. His parents had spent much of their lives exploring the Rift Valley and working at Olduvai in Northern Tanzania.

In contrast Leakey undertook his first field trip to the Omo valley in Ethiopia. In 1965 he shifted his interest to Lake Turkana in northern Kenya, concentrating his work in the Koobi Fora area. At the same time he was appointed to the directorship of the Kenya National Museum, Nairobi.

In 1972 he made his first major find at Koobi Fora. This was a skull with a brain capacity of about 800 cc, given the number 1470. Leakey identified 1470 as Homo rather than an australopithecine precursor, and took it to be Homo habilis. The age of the skull, however, was in dispute varying from 1.8 to 2.4 million years; the former age was eventually accepted.

In 1975 a second skull was found, this time Homo erectus, a more advanced form than 1470. By this time Leakey was finding that the demands of administration, producing TV series, and writing popular accounts of his work were limiting his research activities. Moreover, he suffered the onset of kidney failure in 1979. The donation of a kidney by his brother Philip restored Leakey to what he termed in his autobiography One Life (1983), the beginning of his “second life.” Much of this second life has been devoted to conservation and Leakey has been a leading figure in the fight to preserve the African elephant by banning the trade in ivory. In 1990 he was appointed director and executive chairman of the Kenyan Wildlife Service.

However, during his fight against ivory smugglers, Leakey made many enemies. His determination, outspokenness, and ruthlessness alienated him from many leading Kenyan politicians and administrators. Consequently, in 1994, he resigned his post with the Kenyan Wildlife Service and decided to enter politics, despite an airplane crash in 1993 that led to the amputation of both legs. In 1995 Leakey formed a new political party, Safina (Noah's Ark), and announced his intention to challenge the ruling KANU (Kenya African National Union) in the next elections.

Throughout his career Leakey has described the development of humans in terms similar to those adopted by his father. He has rejected the claims of Don Johanson that ‘Lucy’, Australopithecus afarensis, is a joint ancestor of Homo as well as the australopithecines first described by Raymond Dart. Leakey has continued to claim that it is too simple to present the human evolutionary tree as having only two branches; rather, there were at least three, and it was more than likely that future discoveries would add to the number. Human evolution, for Leakey, seems more like a bush than a tree.