Khun Sa (b 1933) is a Burmese warlord and ex-leader of the Shan United Army . He is also dubbed the "Opium King" due to his opium trading in the so-called Golden Triangle.

Khun Sa was born Chan Shi-fu in 1933. When his mother married a Shan prince, he adopted the name Khun Sa, meaning "Prince Prosperous". In his youth he served with Kuomingtang but left to form his own army of a few hundred men. In 1963 he reformed it into a Ka Kwe Ye , local militia loyal to Burmese government. Ka Kwe Ye received money, uniforms and weapons in return to fighting the Shan rebels.

When Khun Sa had expanded his army to 800 men, he stopped cooperating with the Burmese government, took control of large area in Shan and Wa states and expanded into opium production. In 1967 he clashed with the Kuomingtang in Shan State, which resulted in his defeat demoralizing him and his forces. In 1969 Rangoon government captured him. He was freed in 1973 when his second-in-command abducted two Russian doctors and demanded his release. By 1976 he had returned to opium smuggling, and set up a base in northern Thailand in the town of Ban Hin Taek. He renamed his group the Shan United Army and began ostensibly fighting for Shan autonomy against the Burmese Government.

In 1985 Khun Sa joined forces with the Tai Revolutionary Council of Moh Heng . Through that alliance he both gained control of the whole Thai-Burma border area from Mae Hong Son to Mae Sai and become one of the principal figures in opium smuggling in the Golden Triangle.

In 1989 Khun Sa was charged in New York court trying to import 1,000 tons of heroin. He had proposed that the USA would buy his entire opium production so he would not sell it on the international narcotics market.

Khun Sa surrendered to Burmese officials in January 1996, reputedly because he did not want to face drug smuggling charges in the USA. US officials had promised $2 million reward for his arrest. Burmese officials have refused to extradite him, and now he lives in the Rangoon area with significant investments in Rangoon, Mandalay and Taunggyi.