George Herbert Leigh-Mallory (18 June 1886 – 8 or 9 June 1924) was an English mountaineer who participated in the first three British Mount Everest expeditions from the early to mid-1920s. He and his climbing partner Andrew "Sandy" Irvine were reported to be last seen ascending near Everest's summit during the 1924 expedition, sparking debate as to whether they reached it before they died.
Born in Cheshire, England, Mallory became a student at Winchester College, where a teacher recruited him for an excursion in the Alps, and he developed a strong natural climbing ability. After graduating from Magdalene College, Cambridge, where he became friends with prominent intellectuals, he taught at Charterhouse School while honing his climbing skills in the Alps and the English Lake District. He pioneered new routes and became a respected figure in the British climbing community.
His service in the First World War interrupted his climbing, but he returned with renewed vigour after the war. Mallory's most notable contributions to mountaineering were his expeditions to Everest.