| Republic of Vietnam Armed Forces | |
| Native Name: | Quân lực Việt Nam Cộng hòa |
| Motto: | "Tổ Quốc – Danh Dự – Trách Nhiệm" ("Homeland – Honour – Duty") |
| Founded: | 30 December 1955 |
| Disbanded: | 30 April 1975 |
| Branches: | |
| Headquarters: | Saigon, Central-South region of Vietnam |
| Commander-In-Chief: | Ngo Dinh Diem (1955 - 1963) Nguyen Van Thieu (1967 - 1975) |
| Commander-In-Chief Title: | Commander-in-Chief |
| Chief Minister Title: | Prime Minister |
| Minister Title: | Minister of Defense |
| Commander: | See list |
| Commander Title: | Chief of Joint General Staff |
| Active: | 586,838 |
| Deployed: | 1,000,000 in 1972 |
| Foreign Suppliers: |  United States Australia New Zealand Philippines Thailand |
| History: | Military history of Vietnam |
| Ranks: | Ranks and insignia of the Republic of Vietnam |
The Republic of Vietnam Armed Forces (RVNAF; – QLVNCH), were the official armed defence forces of the defunct Republic of Vietnam and were responsible for the defence of the state and the republican regime since its independence from France on 26 October 1955 to its collapse from its northern communist counterparts and the National Liberation Front of South Vietnam (Viet Cong) on 30 April 1975. The Republic of Vietnam Armed Forces day is celebrated in June 19 every years since 1965.
The QLVNCH (also known as the RVNAF) was formally established on December 30, 1955, by the strongman and republican first South Vietnamese president Ngo Dinh Diem, which he declared on October 26 that year after winning a rigged referendum[1] on the future of the State of Vietnam. Created out from ex-French Union Army colonial Indochinese auxiliary units (French: Supplétifs), gathered earlier in July 1951 into the French-led Vietnamese National Army or VNA (Vietnamese: Quân Đội Quốc Gia Việt Nam – QĐQGVN), Armée Nationale Vietnamiènne (ANV) in French, the armed forces of the new state consisted in the mid-1950s of ground, air, and naval branches of service, respectively, the Republic of Vietnam Armed Forces day is also celebrated (mostly by the overseas Vietnamese people) every years in 19 June
Their roles were defined as follows: to protect the sovereignty of the free Vietnamese nation and that of the Republic; to maintain the political and social order and the rule of law by providing internal security; to defend the newly independent Republic of Vietnam from external (and internal) threats; and ultimately, to help reunify Vietnam – divided since the Geneva Accords in July 1955 into two transitional states, one at the north ruled by Ho Chi Minh’s Marxist Lao Dong Party regime and the other in the south under Diem's regime.
The Republic of Vietnam Armed Forces consisted of four military corps (Quân đoàn) as follows:
I Corps headquartered in Da Nang, included five provinces:Tactical zone 11, including 2 provinces Quang Tri and Thua ThienTactical zone 12, including 2 provinces Quang Tin and Quang NgaiQuang Nam Special Zone, including Quang Nam Province and Da Nang City
II Corps headquartered in Nha Trang, but the 2nd Army Corps Command is located in Pleiku (had to move to Nha Trang from mid-March 1975), included 12 provinces:Tactical Zone 22, including 3 provinces Binh Dinh, Phu Yen, Phu BonTactical Zone 23, including 7 provinces Darlac, Khanh Hoa, Ninh Thuan, Binh Thuan, Tuyen Duc, Quang Duc, Lam Dong and Cam Ranh citySpecial area 24, including 2 provinces Kon Tum and Pleiku
III Corps headquartered in Bien Hoa, include 10 provinces:Tactical Zone 31, including 3 provinces Tay Ninh, Hau Nghia, Long AnTactical zone 32, including 3 provinces Phuoc Long, Binh Long, Binh DuongTactical Zone 33, including 4 provinces Binh Tuy, Phuoc Tuy, Long Khanh, Bien Hoa and Vung Tau cityCapital Military District of Saigon - Gia Dinh
IV Corps headquartered in Can Tho, included 16 provinces:Dinh Tuong tactical zone, including 4 provinces Kien Tuong, Dinh Tuong, Go Cong, Kien HoaTactical Zone 41, including 7 provinces Kien Phong, Chau Doc, Vinh Long, Vinh Binh, An Giang, Kien Giang, Sa DecTactical Zone 42, including 5 provinces Phong Dinh, Chuong Thien, Ba Xuyen, Bac Lieu, An Xuyen
On July 1, 1970 the four Corps were redesignated as Corps Tactical Zones (CTZs).