Louis Seymour Bazett Leakey (7 August 1903 – 1 October 1972) was a Kenyan-British palaeoanthropologist and archaeologist whose work was important in demonstrating that humans evolved in Africa, particularly through discoveries made at Olduvai Gorge with his wife, fellow palaeoanthropologist Mary Leakey. Having established a programme of palaeoanthropological inquiry in eastern Africa, he also motivated many future generations to continue this scholarly work. Several members of the Leakey family became prominent scholars themselves.

Another of Leakey's legacies stems from his role in fostering field research of primates in their natural habitats, which he saw as key to understanding human evolution. He personally focused on three female researchers, Jane Goodall, Dian Fossey, and Birutė Galdikas, calling them "The Trimates." Each went on to become an important scholar in the field of primatology. Leakey also encouraged and supported many other PhD candidates, most notably from the University of Cambridge. As well, Leakey played a role in creating organizations for future research in Africa and for protecting wildlife there.