Ellsworth Bunker (born May 11, 1894 in Yonkers, New York, deceased September 30, 1984) was an American diplomat. Trained as a lawyer, Bunker first worked in the private sector before becoming an academic. He then moved to government during the Eisenhower administration. In 1956 he was appointed ambassador to India where he played a crucial role in the covert alliance between the two powers against China. He was replaced by John Kenneth Galbraith in 1961.

After a period back in Washington he was made U.S. ambassador to South Vietnam, 1967-73. Once in Saigon, he strongly supported the war efforts of Presidents Johnson and Nixon, going so far as to applaud US incursions into Laos and Cambodia. Following the conclusion of the Vietnam War, Bunker headed the US team involved in the drawing up of the 1977 Torrijos-Carter Treaties.

He was awarded the Presidential Medal of Freedom twice - the first time in 1963 and the second time in 1967.