Phao Sriyanond (Thai: เผ่า ศรียานนท์, rtgs: Phao Siyanon, March 1, 1910 - November 21, 1960) was a director general of Thailand's national police who was notorious for his excesses against political opponents. He eventually fled the country and died in exile.
An ambitious army officer of Thai-Burmese ancestry, Phao married the daughter of General Phin Choonhavan. He took part in the 1947 coup d'état that ended the last of Pridi Phanomyong's attempts to create democracy in post-World War II Thailand, restoring disgraced Field Marshal Plaek Pibulsonggram to power.
Made deputy director of the police, Phao quickly staged a show trial of the alleged "assassins" of King Ananda Mahidol (Rama VIII), in which three members of the palace staff were found guilty despite any evidence and were eventually executed even though they had earlier been found innocent.
Phao was promoted to the position of director of the police in 1951, by which time he had become one of the country's all-powerful triumvirate. A client of the CIA, Phao received funds and hardware to build his personal fortune, as well as the expertise of American paramilitaries such as James William Lair to turn the police into an alternative force to oppose his military rival, Sarit Thanarat.
Phao established an intimate circle of police officers, known generally as the "knights of the diamond ring", which was notorious for its treatment of opponents of the government and the police generals, even resorting to assassination and murder. Their crimes were many:
Phao was extremely wealthy. He demanded protection money from businessmen, rigged the gold exchange, and blackmailed corporations into giving him huge shareholdings. He also profited greatly from the opium trade. Police units transferred opium from the poppy fields of the Golden Triangle to Bangkok, ready to be exported. Trucks, planes, and boats which had been supplied to the police by the CIA, were instead used to move opium, which the police carefully guarded.