III Corps () was a corps of the

Army of the Republic of Vietnam The Army of the Republic of Vietnam (ARVN; ; ) composed the ground forces of the Republic of Vietnam Military Forces, South Vietnamese military from its inception in 1955 to the Fall of Saigon on 30 April 1975. Its predecessor was the ground forc ...

(ARVN), the army of the nation state of

South Vietnam South Vietnam, officially the Republic of Vietnam (RVN; , VNCH), was a country in Southeast Asia that existed from 1955 to 1975. It first garnered Diplomatic recognition, international recognition in 1949 as the State of Vietnam within the ...

that existed from 1955 to 1975. It was one of four corps in the ARVN, and oversaw the region of the country surrounding the capital

Saigon Ho Chi Minh City (HCMC) ('','' TP.HCM; ), commonly known as Saigon (; ), is the most populous city in Vietnam with a population of around 14 million in 2025. The city's geography is defined by rivers and canals, of which the largest is Saigo ...

. III Corps was activated in September 1959 and controlled the country south of

Phan Thiet Phan may refer to: * Phan (surname), a Vietnamese family name * Phan District, Chiang Rai Province, Thailand * Phan River, Bình Thuận Province, Vietnam * Phan (tray) Phan (, ) is an artistically decorated tray with pedestal. It is common in T ...

excluding Saigon which was controlled by the

Capital Military District Capital Military District (formerly the Capital Military Region) was a corps-level command of the Army of the Republic of Vietnam (ARVN), the army of the nation state of South Vietnam that existed from 1955 to 1975. It encompassed the capital Saig ...

(CMD). In 1962, President

Ngô Đình Diệm Ngô Đình Diệm ( , or ; ; 3 January 1901 – 2 November 1963) was a South Vietnamese politician who was the final prime minister of the State of Vietnam (1954–1955) and later the first president of South Vietnam ( Republic of ...

decided to split the Corps into two, the former III Corps area being reduced in size to cover the area northeast of Saigon and the newly created

IV Corps 4 Corps, 4th Corps, Fourth Corps, or IV Corps may refer to: France * 4th Army Corps (France) * IV Cavalry Corps (Grande Armée), a cavalry unit of the Imperial French Army during the Napoleonic Wars * IV Corps (Grande Armée), a unit of the Imperi ...

taking over the west and southwest. The Fifth Division based in

Bien Hoa Bien may refer to: * Bien (newspaper) * Basic Income Earth Network * Bień, Poland * "Bien", a song by Tini from ''Un Mechón de Pelo'' * Gertrud Bien Gertrud Bien (1881–1940) was an Austrian pediatrician and one of the first female medical stu ...

on the northern outskirts of Saigon was a part of III Corps, and due to the division's close proximity to the capital was a key factor in the success or failure of the various coup attempts in the nation's history. As from 7 June 1966 the CMD became a subordinate command of III Corps. Map of III CTZ

Divisions

File:ARVN 5th Division SSI.svg, 5th Infantry Division File:ARVN 18 Division SSI.svg, 18th Infantry Division File:ARVN 25th Infantry Division SSI.svg, 25th Infantry Division

References

Corps level formations of South Vietnam Military units and formations established in 1955 Military units and formations disestablished in 1975 1955 establishments in South Vietnam Saigon in the Vietnam War {{mil-unit-stub