On April 30, 1975, North Vietnamese Army (PAVN) forces entered Saigon, the capital of South Vietnam. General Duong Van Minh, who had assumed the presidency of the Republic of South Vietnam just two days earlier on April 28, broadcast an announcement at 10:24 AM that the South Vietnamese government surrendered unconditionally to the North Vietnamese forces. The Vietnam War, which had consumed American national life for more than a decade and had cost 58,220 American lives, had ended in communist victory. The American military commitment had officially ended in January 1973 with the Paris Peace Accords; the last American combat troops had departed in March 1973. But the war between North and South Vietnam had continued, with South Vietnamese forces mounting a desperate defense. On May 1, 1975, that defense had collapsed utterly.

Operation Frequent Wind, the final American evacuation from Saigon, had been conducted over April 29–30. Helicopters, primarily Marine CH-46 and CH-53 helicopters launched from the USS Coral Sea and other ships positioned off the coast, evacuated American citizens and Vietnamese allies from Saigon. By the time the last helicopter lifted off the roof of the U.S. Embassy at 7:53 AM on April 30, approximately 1,373 American citizens and 5,595 Vietnamese had been evacuated. The image of the last helicopter departing the embassy roof, with crowds of Vietnamese citizens desperate to escape the advancing North Vietnamese army, became the iconic image of the fall of Saigon. Thousands of Vietnamese who had worked with American military and government forces remained behind, facing an uncertain—and likely dire—future under communist rule.

On May 1, North Vietnamese forces took control of all government buildings in Saigon. The presidential palace was occupied. The National Assembly building was secured. Radio stations fell under military control. Tan Son Nhut Air Base, South Vietnam's largest military airfield, was seized by PAVN forces. The military command structure of the South Vietnamese armed forces ceased to exist; some officers attempted to escape by boat; others surrendered. An estimated 130,000 South Vietnamese military officers, civil servants, police, and others who had worked with the American or South Vietnamese governments were taken into custody and placed in "re-education camps." These camps were harsh, poorly supplied, and many detainees would remain imprisoned for years or even decades. Estimates suggest that 10,000 to 30,000 of the detainees would eventually die in the camps from disease, malnutrition, or abuse.

The financial assets of the Republic of South Vietnam were captured by North Vietnamese forces on May 1. Approximately $60 million in gold and other currency, stored in South Vietnamese vaults, fell into North Vietnamese control. These resources, combined with Soviet and Chinese assistance, would help the new unified Vietnamese government survive the transition to a centrally planned communist economy.

The symbolic renaming of Saigon to Ho Chi Minh City occurred on May 1, though formal ratification came later. The new government, led by Party Chairman Le Duan and General Secretary Truong Chinh of the Lao Dong (Communist Party), immediately began the process of consolidating communist rule, disarming South Vietnamese military units, and incorporating South Vietnam into the Democratic Republic of Vietnam. The unification would be formalized on July 2, 1976, when the National Assembly of the newly united Vietnam adopted a new constitution.

The human cost of the Vietnam War was staggering. American combat casualties totaled 58,220 killed and approximately 300,000 wounded. South Vietnamese military casualties totaled approximately 250,000 killed, with additional numbers wounded. North Vietnamese and Viet Cong casualties were estimated at 1.1 million or more killed. Civilian casualties—deaths among Vietnamese civilians caught in the crossfire or killed deliberately in atrocities like the My Lai massacre—numbered in the hundreds of thousands. The bombing of Cambodia and Laos, which had been conducted secretly and had involved more tonnage of explosives than the atomic bombing of Hiroshima and Nagasaki, had killed an estimated 150,000 to 500,000 civilian casualties.

The exodus began immediately. Knowing that the fall of Saigon was imminent and fearing communist re-education camps or political persecution, South Vietnamese civilians and military personnel attempted to flee. The "boat people" exodus, which would eventually see 800,000 to 1 million Vietnamese flee over the following decade, began with desperate attempts by individuals and families to escape by boat on May 1 and immediately thereafter. Many drowned en route. Pirate attacks on refugee boats were common. Those who survived the sea voyage faced uncertain futures in refugee camps in Thailand, Malaysia, Hong Kong, and other Southeast Asian nations. International resettlement, particularly to the United States, Australia, Canada, and France, would eventually occur, but the process was slow and thousands died waiting.

In the United States, the fall of Saigon was received with a complex mix of emotions: relief that American military involvement had ended, grief over the loss of the war and American service members, and moral anxiety about the fate of South Vietnamese allies left behind. The war had divided American society for over a decade; the fall of Saigon did not heal those divisions immediately, but it did mark the psychological and strategic end of the American war effort. The questions about why the war was fought, whether it was winnable, and whether American intervention had been justified would preoccupy American public consciousness for years. The War Powers Act of 1973, passed while fighting was still ongoing, represented Congressional determination to prevent future unilateral presidential war-making without explicit Congressional authorization.

May 1, 1975, marked the end of American military involvement in Southeast Asia—the longest and most divisive war in American history since the Civil War. The consequences of the war—the social divisions within the United States, the questioning of American military power and strategy, the refugee crises, the trauma of the veterans, and the transformation of Southeast Asia under communist rule—would ripple through the remainder of the 20th century.