Yuval Noah Harari (Hebrew: יובל נח הררי [juˈval ˈnoaχ haˈʁaʁi]; born 1976) is an Israeli medievalist, military historian, public intellectual, and popular science writer. He currently serves as professor in the Department of History at the Hebrew University of Jerusalem. His first bestseller, Sapiens: A Brief History of Humankind (2011), is based on his lectures to an undergraduate world history class. Among his other works, are other bestsellers like Homo Deus: A Brief History of Tomorrow (2016), 21 Lessons for the 21st Century (2018), and Nexus: A Brief History of Information Networks from the Stone Age to AI (2024). His published work examines themes of free will, consciousness, intelligence, happiness, and suffering.

In his first book, Harari writes about a "cognitive revolution" that supposedly occurred roughly 70,000 years ago when Homo sapiens supplanted the rival Neanderthals and other species of the genus Homo, developed language skills and structured societies, and ascended as apex predators, aided by the First Agricultural Revolution and accelerated by the Scientific Revolution, which have allowed humans to approach near mastery over their environment. Furthermore, he examines the possible consequences of a futuristic biotechnological world in which intelligent biological organisms are surpassed by their own creations; he has said, "Homo sapiens as we know them will disappear in a century or so". Although his books have received considerable commercial success since the publication of Sapiens, Harari's work has been more negatively received in academic circles.