Peter John Wyllie is a retired petrologist, author and explorer. Born in 1930 in London, Wyllie studied at St Andrews University where he gained a degree in Physics and Geology in 1952. Following this he joined the British North Greenland Expedition as a geologist. The expedition was a pioneering British-led 2 year scientific expedition to the North Greenland Ice Sheet. The expedition sought to conduct research in many areas including geology, seismology, meteorology, gravimetry, physiology and the logistics of operating in a polar climate for prolonged periods.

Following the expedition Wyllie gained a PHD in geology and went on to have a successful academic career in the field. Emigrating to the United States in the late 1950s he was appointed professor of geology at California Institute of Technology in 1983, a position which he held until his retirement in 1999. During his career as an academic Wyllie made notable contributions to research in the field of petrology and authored 2 textbooks in the fields of plate tectonics and magmatism.