Guy Henry Bullock (23 July 1887 – 12 April 1956) was a British diplomat who is best known for his participation in the 1921 British Mount Everest reconnaissance expedition. As expedition mountaineers, he and George Mallory found a northern access route to Everest by climbing the 6,849-metre (22,470 ft) Lhakpa La col above the East Rongbuk Glacier and by going on to reach the North Col at 7,020 metres (23,030 ft). They did not, however, reach the summit of Mount Everest.