McNeill attended Swarthmore College and Duke University before joining the Georgetown University faculty in 1985. He has received two Fulbright awards, as well as fellowships from the Guggenheim Foundation, the MacArthur Foundation, and the Woodrow Wilson Center, as well as a visiting appointment at the Ecole des Hautes Etudes in Sciences Sociales. His writings include The Atlantic Empires of France and Spain, 1700-1765 (1985); The Mountains of the Mediterranean World (1992); and Something New Under the Sun: An Environmental History of the Twentieth-Century World (2000), which was co-winner of the World History Association book award, the Forest History Society book prize, and runner-up for the BP Natural World book prize, and was named one of the best books of the year by the London Times. He received the Toynbee Award in 2010 for his academic and public contributions to humanity.