The Khmer Rouge (Khmer: ខ្មែរក្រហម Khmer Krahom; English: Red Khmers) was the name given to the followers of the Communist Party of Kampuchea in Cambodia. It was formed in 1968 as an offshoot of the Vietnam People's Army from North Vietnam. It was the ruling party in Cambodia from 1975 to 1979, led by Pol Pot, Nuon Chea, Ieng Sary, Son Sen, and Khieu Samphan. Democratic Kampuchea was the name of the state as controlled by the government of the Khmer Rouge from 1975 to 1979.

The organization is remembered especially for orchestrating the Cambodian Genocide, which resulted from the enforcement of its social engineering policies. Its attempts at agricultural reform led to widespread famine, while its insistence on absolute self-sufficiency, even in the supply of medicine, led to the deaths of thousands from treatable diseases such as malaria. Arbitrary executions and torture carried out by its cadres against perceived subversive elements, or during purges of its own ranks between 1975 and 1978, are considered to have constituted genocide. By 1979, the Khmer Rouge had fled the country, while the People's Republic of Kampuchea was being established. The governments-in-exile (including the Khmer Rouge) still had a seat in the UN at this point but it was later taken away, in 1993, as the monarchy was restored and the country underwent a name change to the Kingdom of Cambodia. A year later thousands of Khmer Rouge guerrillas surrendered themselves in a government amnesty. In 1996, a new political party the Democratic National Union Movement was formed by Ieng Sary, who was granted amnesty for all of his roles as the deputy leader of the Khmer Rouge. The organisation itself was officially dissolved sometime in December 1999.