Sir John Addis KCMG (11 June 1914 – 31 July 1983) was a British diplomat, ambassador to Laos, the Philippines and China, and a collector of Ming porcelain which he gave to the British Museum.
John Mansfield Addis was educated at Rugby School and Christ Church, Oxford, and joined the Foreign Office in 1938. After postings at Nanking, Peking and the Foreign Office, he was ambassador to Laos 1960–62; Fellow at the Harvard Center for International Affairs 1962–63; ambassador to the Philippines 1963–70; Senior Civilian Instructor at the Imperial Defence College 1970–71; and ambassador to China 1972–74. After retiring from the Diplomatic Service, Addis was Senior Research Fellow in Contemporary Chinese Studies at Wolfson College, Oxford, 1975–82. He was a trustee of the British Museum.
Addis was appointed CMG in the New Year Honours of 1959 and knighted KCMG in the New Year Honours of 1973.