Arthur Hobson Dean (October 16, 1898 – November 30, 1987) was a New York City lawyer and diplomat who was viewed as one of the leading corporate lawyers of his day, as well having served as a key advisor to numerous U.S. presidents.^[1]

Dean was a native of Ithaca, New York, and attended Ithaca High School and then Cornell University. After serving in the U.S. Navy during World War I, he received both a bachelor's and LL.B degree from Cornell, in 1921 and 1923, respectively, and was the managing editor of the Cornell Law Quarterly^[2]

Dean was chairman and senior partner of Sullivan & Cromwell, where he worked closely with John Foster Dulles. He was the chief U.S. negotiator at Panmunjeom where he helped negotiate the Korean Armistice Agreement, which ended the Korean War,^[3][4] and helped draft and negotiate the Nuclear Test Ban Treaty in 1963.^[5]

Dean was a member and later served on the board of directors of the Council on Foreign Relations, the Asia Society, and served as a delegate to the United Nations. He was a member of the steering committee of the Bilderberg Group^[6] and participated in 14 conferences between 1957 and 1975.

Dean's official papers are maintained at Cornell University Library, of which he was a major patron.^[7]