The Laotian Civil War (1959–1975) was a civil war in Laos waged between the Communist Pathet Lao and the Royal Lao Government from 23 May 1959 to 2 December 1975. It is associated with the Cambodian Civil War and the Vietnam War, with both sides receiving heavy external support in a proxy war between the global Cold War superpowers. It is known as the Secret War among the American CIA Special Activities Center, and Hmong and Mien veterans of the conflict.

The Kingdom of Laos was the form of government in Laos from 1947 to 1975. Located in Southeast Asia at the heart of the Indochinese Peninsula, it was bordered by Burma and China to the northwest, North Vietnam to the east, Cambodia to the southeast, and Thailand to the west and southwest. The country was governed as a constitutional monarchy beginning with its independence on 9 November 1953. It survived until December 1975, when its last king, Sisavang Vatthana, surrendered the throne to the Pathet Lao during the civil war in Laos, who abolished the monarchy in favour of a Marxist–Leninist state called the Lao People's Democratic Republic, which has controlled Laos ever since.