Ralph Johnson Bunche (/bʌntʃ/ BUNCH; August 7, 1904 – December 9, 1971) was an American political scientist, diplomat, and leading actor in the mid-20th-century decolonization process and US civil rights movement, who received the 1950 Nobel Peace Prize for his late 1940s mediation in the Arab-Israeli conflict. He is the first black Nobel laureate and the first person of African descent to be awarded a Nobel Prize. He was involved in the formation and early administration of the United Nations (UN), and played a major role in both the decolonization process and numerous UN peacekeeping operations.

Bunche served on the US delegation to both the Dumbarton Oaks Conference in 1944 and United Nations Conference on International Organization in 1945 that drafted the UN charter. He then served on the American delegation to the first session of the United Nations General Assembly in 1946 and joined the UN as head of the Trusteeship Department, beginning a long series of troubleshooting roles and responsibilities related to decolonization. In 1948, Bunche became an acting mediator for the Middle East, negotiating an armistice between Egypt and Israel. For this success he was awarded the Nobel Peace Prize in 1950.

Bunche continued to serve at the UN, working on crises in the Sinai (1956), the Congo (1960), Yemen (1963), Cyprus (1964) and Bahrain in 1970, reporting directly to the UN Secretary-General. He chaired study groups dealing with water resources in the Middle East. In 1957, he was promoted to Under-Secretary-General for special political affairs, having prime responsibility for peacekeeping roles. In 1965, Bunche supervised the cease-fire following the war between India and Pakistan. He retired from the UN in June 1971, dying six months later.

In 1963, he was awarded the Presidential Medal of Freedom by President John F. Kennedy. At the UN, Bunche gained such fame that Ebony magazine proclaimed him perhaps the most influential African American of the first half of the 20th century and "[f]or nearly a decade, he was the most celebrated African American of his time both [in the US] and abroad."

Bunche was born in Detroit, Michigan, in 1904 and baptized at the city's Second Baptist Church. When Ralph was a child, his family moved to Toledo, Ohio, where his father looked for work. They returned to Detroit in 1909 after his sister Grace was born, with the help of their maternal aunt, Ethel Johnson. Their father did not live with the family again after Ohio and had not been "a good provider". But he followed them when they moved to New Mexico.

Because of the declining health of his mother and uncle, the family moved to Albuquerque, New Mexico, in 1915. His mother, "a musically inclined woman who contributed much to what her son called a household 'bubbling over with ideas and opinions'", died in 1917 from tuberculosis, and his uncle shortly thereafter. Thereafter, Bunche was raised by his maternal grandmother, Lucy Taylor Johnson, whom he credited with instilling in him his pride in his race and his self-belief.

In 1918, Lucy Taylor Johnson moved with the two Bunche grandchildren to the South Central neighborhood of Los Angeles.

Bunche was a brilliant student, a debater, athlete and the valedictorian of his graduating class at Jefferson High School. He attended the University of California, Los Angeles (UCLA) as a political science student, and graduated summa cum laude and Phi Beta Kappa in 1927 as the valedictorian of his class. Using the money his community raised for his studies and a graduate scholarship at Harvard University, he earned a doctorate in political science.