Bunche was born in Detroit, Michigan in 1904 and baptized at the city’s Second Baptist Church. His father Fred Bunche was a barber and his mother, Olive Agnes (née Johnson), was an amateur musician, from a “large and talented family.” Her siblings included Charlie and Ethel Johnson.

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, Ralph moved with his maternal grandmother, Lucy Taylor Johnson, to Albuquerque, New Mexico in 1915. His mother died in 1917; his uncle committed suicide three months later. Bunche was 13 years old.

In 1918, Lucy Taylor Johnson moved with the two Bunche grandchildren to the South Central neighborhood of Los Angeles, which was then mostly white. Fred Bunche later remarried, and Ralph never saw him again.

Bunche was a brilliant student, a debater, and the valedictorian of his graduating class at Jefferson High School. He attended the University of California, Los Angeles (UCLA), 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.

Bunche earned a master’s degree in political science in 1928 and a doctorate in 1934, while he was already teaching in the Department of Political Science at Howard University, an historically black college. At the time, it was typical for doctoral candidates to start teaching before completion of their dissertations. He was the first African American to gain a PhD in political science from an American university. He published his first book, World View of Race, in 1936. From 1936 to 1938, Ralph Bunche conducted postdoctoral research in anthropology at the London School of Economics (LSE), and later at the University of Cape Town in South Africa.

While teaching at Howard University in 1928, Bunche met Ruth Harris as one of his students. They later started seeing each other and married June 23, 1930. The couple had three children: Joan Harris Bunche (b. 1931), Jane Johnson Bunche (b. 1933), and Ralph J. Bunche, Jr. (b. 1943). His grandson, Ralph J. Bunche III, is the General Secretary of the Unrepresented Nations and Peoples Organization, an international membership organization established to facilitate the voices of unrepresented and marginalised nations and peoples worldwide.

In 1940, Bunche contributed, as an investigative researcher and writer, to Swedish sociologist Gunnar Myrdal’s landmark study of racial dynamics in the U.S., An American Dilemma.

In 1941-43 Bunche worked in the Office of Strategic Services (OSS), the wartime intelligence service, as a senior social analyst on Colonial Affairs. In 1943, he was transferred from the OSS to the State Department. He was appointed Associate Chief of the Division of Dependent Area Affairs under Alger Hiss. With Hiss, Bunche became one of the leaders of the Institute of Pacific Relations (IPR). He participated in the preliminary planning for the United Nations at the San Francisco Conference of 1945. In 2008, the U.S. National Archives and Records Administration released a 51-page PDF of his OSS records, which is available online.

Near the close of World War II in 1944, Bunche took part in planning for the United Nations at the Dumbarton Oaks Conference, held in Washington, D.C. He was an adviser to the U.S. delegation for the “Charter Conference” of the United Nations held in 1945, when the governing document was drafted. Together with First Lady Eleanor Roosevelt, Bunche was instrumental in the creation and adoption of the Universal Declaration of Human Rights. Bunche urged African-Americans to take UN positions. “Negroes ought to get busy and prepare to obtain some of the jobs in the United Nations’ set-up,” he counseled. “There are going to be all kinds of jobs and Negroes should attempt to get jobs on all levels. Some organization should be working on this now.”

Beginning in 1947, Bunche was involved with trying to resolve the Arab–Israeli conflict in Palestine. He served as assistant to the United Nations Special Committee on Palestine, and thereafter as the principal secretary of the UN Palestine Commission. In 1948, he traveled to the Middle East as the chief aide to Sweden’s Count Folke Bernadotte, who had been appointed by the UN to mediate the conflict. These men chose the island of Rhodes for their base and working headquarters. In September 1948, Bernadotte was assassinated in Jerusalem by members of the underground Jewish Lehi group, which was led by Yitzhak Shamir.

Following the assassination, Bunche became the UN’s chief mediator; he conducted all future negotiations on Rhodes. The representative for Israel was Moshe Dayan; he reported in memoirs that much of his delicate negotiation with Bunche was conducted over a billiard table while the two were shooting pool. Optimistically, Bunche commissioned a local potter to create unique memorial plates bearing the name of each negotiator. When the agreement was signed, Bunche awarded these gifts. After unwrapping his, Dayan asked Bunche what might have happened if no agreement had been reached. “I’d have broken the plates over your damn heads,” Bunche answered. For achieving the 1949 Armistice Agreements, Bunche received the Nobel Peace Prize in 1950. He continued to work for the United Nations, mediating in other strife-torn regions, including the Congo, Yemen, Kashmir, and Cyprus. Bunche was appointed Under-Secretary-General of the United Nations in 1968.

Bunche lived in the Kew Gardens neighborhood of Queens, New York, in a home purchased with his Nobel Prize money, from 1953 until his death. Like many other people of color, Bunche continued to struggle against racism across the United States and sometimes in his own neighborhood. In 1959, he and his son, Ralph, Jr., were denied membership in the West Side Tennis Club in the Forest Hills neighborhood of Queens. After the issue was given national coverage by the press, the club offered the Bunches an apology and invitation of membership. The official who had rebuffed them resigned. Bunche refused the offer, saying it was not based on racial equality and was an exception based only on his personal prestige.

Bunche was an active and vocal supporter of the Civil Rights Movement in the United States. He participated in the 1963 March on Washington, where Martin Luther King Jr. gave his “I Have a Dream” speech, and also in the Selma to Montgomery, Alabama march in 1965, which contributed to passage of the landmark Voting Rights Act of 1965 and federal enforcement of voting rights.

On October 9, 1966, their daughter Jane Bunche Pierce fell or jumped from the roof of her Riverdale, Bronx apartment building; her death was believed to be suicide. She left no note. She and her husband Burton Pierce, a Cornell alumnus and labor relations executive, had three children. Their apartment was on the first floor of the building.