The 1975 spring offensive (Vietnamese: chin dch ma Xun 1975), officially known as the general offensive and uprising of spring 1975 (Vietnamese: Tng tin cng v ni dy ma Xun 1975) was the final North Vietnamese campaign in the Vietnam War that led to the capitulation of Republic of Vietnam. After the initial success capturing Phc Long Province, the North Vietnamese leadership increased the scope of the People's Army of Vietnam's (PAVN) offensive and captured and held the key Central Highlands city of Bun Ma Thut between 10 and 18 March. These operations were intended to be preparatory to launching a general offensive in 1976.

Following the attack on Bun Ma Thut, the Republic of Vietnam realized they were no longer able to defend the entire country and ordered a strategic withdrawal from the Central Highlands. The retreat from the Central Highlands, however, was a debacle as civilian refugees fled under fire with soldiers, mostly along a single highway reaching from the highlands to the coast. This situation was exacerbated by confusing orders, lack of command and control, and a well-led and aggressive enemy, which led to the utter rout and destruction of the bulk of South Vietnamese forces in the Central Highlands. A similar collapse occurred in the northern provinces.

Surprised by the rapidity of the ARVN collapse, North Vietnam transferred the bulk of its northern forces more than 350 miles (560 km) to the south in order to capture the South Vietnamese capital of Saigon in time to celebrate their late President Ho Chi Minh's birthday and end the war. South Vietnamese forces regrouped around the capital and defended the key transportation hubs at Phan Rang and Xun Lc, but a loss of political and military will to continue the fight became ever more manifest. Under political pressure, South Vietnamese President Nguyn Vn Thiu resigned on 21 April, in hopes that a new leader that was more amenable to the North Vietnamese could reopen negotiations with them. It was, however, too late. Southwest of Saigon IV Corps, meanwhile, remained relatively stable with its forces aggressively preventing VC units from taking over any provincial capitals. With PAVN spearheads already entering Saigon, the South Vietnamese government, then under the leadership of Dng Vn Minh, capitulated on 30 April 1975.

Cao Văn Viên (December 21, 1921 – January 22, 2008) was one of only two South Vietnamese four-star army generals in the history of the Army of the Republic of Vietnam during the Vietnam War. He rose to the position of Chairman of the South Vietnamese Joint General Staff. Considered one of "the most gifted" of South Vietnam's military leaders, he was previously called an "absolute key figure" and one of "the most important Vietnamese military leaders" in the U.S.-led fighting during the Vietnam War. Along with Trần Thiện Khiêm he was one of only two four-star generals in the entire history of South Vietnam.