William Butts Macomber Jr. (March 28, 1921 – November 19, 2003) was an American diplomat who served in several positions in the United States Department of State. He was the 12th president of the Metropolitan Museum of Art.

Macomber was born in Rochester, New York, on March 28, 1921. He attended Phillips Academy, graduating in 1940, and Yale University, graduating in 1943.^[2]

During World War II, he served in the United States Marine Corps, assigned to the Office of Strategic Services. After the war, he returned to Yale, receiving a master's degree in 1947. He next attended Harvard Law School, receiving his law degree in 1949. He then worked at Boston University as a lecturer in government, then moved on to the University of Chicago, receiving a second master's degree in 1951.^[2]

Macomber worked in the U.S. Government for decades, serving under five presidents. His positions were unstable, however, because he was always a political appointee and not a career Foreign Service officer.^[3]

Macomber joined the Central Intelligence Agency in 1951. Two years later, he moved to the United States Department of State as a special assistant of intelligence. In 1957, President Dwight D. Eisenhower nominated Macomber as assistant secretary of state for legislative affairs and served until February 27, 1961.^[4]

President John F. Kennedy then named Macomber as United States ambassador to Jordan and Macomber held this post from April 5, 1961, until December 25, 1963.^[4] In 1964, he became assistant administrator of the United States Agency for International Development.^[2]

Macomber returned to the office of assistant secretary of state for legislative affairs after he was named to the office by President Lyndon B. Johnson, and Macomber served in this office from March 7, 1967, through October 2, 1969.^[4]

Richard Nixon appointed Macomber deputy under secretary of state for management on September 26, 1969, and he served in this role from October 3, 1969, to April 4, 1973.^[4]

President Richard Nixon appointed him United States ambassador to Turkey on March 27, 1973. He presented his credentials on May 16, 1973, and served until he left his post on June 15, 1977.^[4] In 1975, he published a book, The Angels' Game: A Handbook of Modern Diplomacy. He retired from the United States Foreign Service in 1977.^[4]

Macomber was married to the Boston native and Simmons College graduate, Phyllis Dorothy Bernau (1924–2014) in c. 1964. They lived in a Fifth Avenue apartment and had a summer home in Nantucket, Massachusetts.^[2]

Macomber died of complications related to Parkinson's disease at his home in Nantucket, on November 19, 2003.^[2][7]