Trần Văn Đôn (August 17, 1917 – 1998) was a general in the Army of the Republic of Vietnam, and one of the principal figures in the coup d'état which deposed Ngô Đình Diệm from the presidency of South Vietnam.
Đôn was born in Bordeaux, France. His father was the son of a wealthy Mekong Delta landowner, which allowed him to travel to France to study medicine. It was during this period that Đôn was born. He returned to France as an adult for his university study. He became a French Army officer when World War II began, later training at École spéciale militaire de Saint-Cyr, the French equivalent of West Point.
He returned to Vietnam and served in the French-backed Vietnamese National Army of the French-backed State of Vietnam, fighting against the Việt Minh in the First Indochina War. Đôn was a colonel in 1955, when he and then fellow colonel Dương Văn Minh helped Ngô Đình Diệm establish himself in control of South Vietnam following the Geneva Accords and partition by helping to subdue the private armies of the Hòa Hảo and Cao Đài religious sects, as well as the Bình Xuyên organized crime syndicate. Both were immediately promoted to the rank of general. With the proclamation of the Republic of Vietnam, military officers were faced with becoming Vietnamese citizens if they wanted to remain in their positions. Đôn became a Vietnamese citizen.
Đôn became Diệm's chief of staff and presided over a ceremony in Saigon in which the French-style military rank insignias were burnt and replaced with American-inspired new insignias. In the early 1960s, he commanded the I-Corps of the Army of the Republic of Vietnam, which operated in the far north of South Vietnam, in the border region along the demilitarised zone. He led his forces into the mountainous areas of the Central Highlands to flush out pockets of Việt Cộng resistance and to prevent further infiltration from North Vietnam. In all, his command took in five provinces. He often came into dispute with Diệm's brother, Ngô Đình Cẩn, who had his own autonomous private army and secret police and ruled the northern border regions of South Vietnam arbitrarily. Đôn was removed from command of troops and made the Joint Chief of Staff, where he was confined to an office with no troops. His work was mainly travelling to the airport to greet visiting American dignitaries. Diệm feared that the respect that Đôn commanded could make him a possible rival for power, as the army leadership was selected for the purpose of preserving Diệm in power, rather than defeating the communists.
Đôn, then army Chief of Staff, organised discontented officers, and in mid-1963 began meeting with Lucien Conein, a French-born CIA agent in Saigon with whom he culturally related. His closest confidant was his brother-in-law, General Lê Văn Kim, who was also trained in France. In August, Đôn and other generals proposed to Diệm that he declare martial law so that they could prosecute the war more effectively among the unrest. Their real purpose was to strengthen their control in preparation for a coup. Diệm agreed, although he arranged that the army would raid the Xá Lợi Pagoda and attack Buddhist dissidents unhappy with Diệm's oppressive sectarianism and his discriminatory policies.
In the wake of the raids, Đôn attempted to win over General Tôn Thất Đính, the commander of the forces which surrounded Saigon, so that he could encircle Diệm. Đính, who was regarded as being vain, was reveling after having taken credit for the Pagoda raids, even though they were performed by the Special Forces of Colonel Lê Quang Tung. Đôn organised for a national inspection tour with Đính, and played to his ego. Đôn organised many parties for Đính, and told him that he was a national hero worthy of political authority. He even bribed Đính's soothsayer to predict his elevation to political authority. After Đính asked Diệm for the interior ministry post in front of his colleagues and was rebuked and sent off duty in front of his colleagues, Đính changed sides. Đôn and Đính then signed orders transferring the forces based around Mỹ Tho, 60 kilometres south of Saigon from General Huỳnh Văn Cao, a Diệm loyalist, to General Nguyễn Hữu Có. This gave the plotters complete encirclement of Saigon.
On 1 November, Đôn convened a group of South Vietnamese officers at staff headquarters at Tân Sơn Nhứt Airport at 1330, and announced that a military revolutionary council was taking power in a coup. Diệm repeatedly asked Đôn to call off the coup and negotiate governance reforms, but this was refused, since the 1960 South Vietnamese coup attempt was crushed by loyalists after the rebels stalled for negotiations. Đôn promised Diệm safe passage from the country, but Major Nguyễn Văn Nhung, one of the arresting officers, shot Diệm and Nhu.
Đôn then served in the military junta that resulted from the coup, as defense minister until it was deposed three months later in the 1964 South Vietnamese coup led by General Nguyễn Khánh. Khánh, unhappy with his dividend from the 1963 coup, enacted retribution against Đôn and Kim. He arrested both, claiming that they were part of a neutralist plot with the Việt Cộng and taken to Đà Lạt. The generals were interrogated for five and a half hours, mostly about details of their coup which were already known, rather than the original charge of promoting neutralism. The court deliberated for nine hours, and when it reconvened for the verdict, Khánh stated, "We ask that once you begin to serve again in the army, you do not take revenge on anybody." The tribunal then "congratulated" the generals, but found that they were of "lax morality", unqualified to command, and "lack of a clear political concept". Kim was put under house arrest for six years and Đôn for 18 months. Officers were prepared in Đà Lạt so that they could participate in "research and planning". When Khánh fled the country after being deposed in 1965, he handed over a dossier which cleared Đôn and the other generals of the charges for which they were convicted.
In 1965, Đôn retired and was elected to the Senate in 1967 after topping the elections. He later served as the defense minister, until 29 April 1975, leaving for the United States one day before the fall of Saigon.