Chang Myon (John M. Chang; 1899-1966), president of the Republic of Korea in 1950, 1952, and again in 1960.

Chang was born in Inch'on to a middle-class Catholic family of northwestern Korean origin that was engaged in customs administration. He graduated from the Suwon Agriculture and Forestry High School and the YMCA English course and studied for five years at Manhattan College, from which he later received a doctoral degree. Chang became principal of the Catholic Tongsung Commercial School in Seoul from 1931 until the liberation of Korea in 1945, leading a quiet, neutral life in the struggle against Japan. Entering conservative postwar political life, he became a member of both the Interim Legislative Assembly (1946) and the National Assembly (1948), serving in the latter year as Korean delegate to the third General Assembly of the United Nations. In 1949 he became Korea's first ambassador to the United States, representing Korea during the opening months of the Korean War. From 1951 until May 1952 he served as Syngman Rhee's prime minister. Although he filled these posts with a faultless conscientiousness and an amiable and trustworthy respectability, he was not noted for dynamism or courage.

In the middle of 1952 the rising repression of Rhee's leadership impelled Chang to join the opposition politics of the Democratic Party, whose supreme committee member he became in 1955. In 1956 he was elected vice president on the opposition ticket, defeating Rhee's candidate. Rhee reacted by ignoring and isolating him. As opposition leader, Chang was reelected to the Assembly in 1960 and, following Rhee's overthrow, was narrowly elected prime minister on 19 August 1960. As leader of the new cabinet-responsible system he had advocated, during the succeeding nine months Chang presided over Korea's only fully democratic government.

Chang assembled an able cabinet, but he then reshuffled their positions too frequently. He tried, with indecision and too much caution, to resolve the problems of clamorous new democratic and factional demands and threats of violence, inflation, and chaos. Chang's government was beginning to work more effectively, institute economic planning, and make progress when, for complex and enigmatic reasons, it failed to detect or defend itself from a military coup on 16 May 1961. Chang added to this failure by fleeing to a convent, where he could not be reached for two crucial days. The Chang government resigned on 18 May, ending for a generation Korea's democratic experiment. Thereafter, Chang Myon lived quietly in Seoul until his death.