South Vietnamese opposition figure Phan Quang Đán was elected to the National Assembly, despite soldiers being bussed in to vote multiple times for President Ngô Đình Diệm's candidate.

South Vietnam, officially the Republic of Vietnam, was a country in Southeast Asia that existed from 1955 to 1975. It first garnered international recognition in 1949 as the associated State of Vietnam within the French Union, with its capital at Saigon. Since 1950, it was a member of the Western Bloc during the Cold War. Following the 1954 partition of Vietnam, it became known as South Vietnam and was established as a republic in 1955. South Vietnam was bordered by North Vietnam to the north, Laos to the northwest, Cambodia to the southwest, and Thailand across the Gulf of Thailand to the southwest. Its sovereignty was recognized by the United States and 87 other nations, though it failed to gain admission into the United Nations as a result of a Soviet veto in 1957. It was succeeded by the Republic of South Vietnam in 1975. In 1976, the Republic of South Vietnam and North Vietnam merged to form the Socialist Republic of Vietnam.

Phan Quang Đán was a Vietnamese political opposition figure who was one of only two non-government politicians who won a seat in the 1959 South Vietnamese election for the National Assembly. Subsequently, he was arrested by the forces of President Ngô Đình Diệm and not allowed to take his seat. The most prominent dissident during the rule of Diệm, he is remembered more for his incarceration than his activities after Diệm's fall, when he became a cabinet minister.

Parliamentary elections were held in South Vietnam on 30 August 1959, resulting in an overwhelming victory for President Ngô Đình Diệm and the government. The regime won all but two of the 123 seats in the National Assembly, taken by five pro-government political parties and pro-government independent candidates. The elections allowed some liberalization in terms of freedom of speech, but the Diệm regime continued to maintain rigid control over the election process. Despite considerable efforts in preventing a small number of opposition candidates from standing during the election through the use of army soldiers bussed in to stuff ballot boxes to support the pro-government candidates, two independent candidates from the opposition were elected – Phan Quang Đán and Phan Khắc Sửu. However, during the first inaugural session of the National Assembly, Đán and another independent deputy, Nguyễn Trân were not permitted to attend and were arrested and charged with electoral fraud. The election as a whole was described by a 1966 CIA report as the "dirtiest and most openly rigged" of all South Vietnamese elections.