Pridi Phanomyong (born May 11, 1900, Ayutthaya, Siam [now Thailand]—died May 2, 1983, Paris, France) was a Thai political leader who was one of the instigators of the June 1932 constitutional revolution and was made prime minister in 1946.

After studies at the Royal Law School, Pridi won a government scholarship to study law in France; he earned a doctorate in law from Paris in 1927. While in Paris he was strongly influenced by French socialism, and, with other students, including Luang Phibunsongkhram, he began plotting the overthrow of the Thai absolute monarchy. On return to Thailand the conspirators intensified their efforts, and on June 24, 1932, they carried out a bloodless coup d’état that forced King Prajadhipok to accept a constitution. As the leading ideologue of the ruling People’s Party, Pridi helped write the constitution of December 1932, and in 1933 he announced a draft economic policy that envisioned state ownership of all industrial and commercial enterprises. The uproar over this plan forced Pridi into temporary exile abroad. On his return he served as minister of the interior and minister of foreign affairs and founded the University of Moral and Political Science (now Thammasat University). He served as minister of finance (1938–41) under Phibunsongkhram but resigned in protest against pro-Japanese policies and was appointed regent for the boy king Ananda Mahidol, then at school in Switzerland. As regent, Pridi directed the anti-Japanese underground Free Thai Movement in the later years of the war and engineered the downfall of Phibunsongkhram’s government in 1944. Over the next two years, Pridi was the real power behind successive civilian governments as Thailand, successfully avoiding treatment as an ally of Japan, regained international respectability.

In March 1946 Pridi himself became prime minister, the first to have been popularly elected. Public support for his government was shattered, however, after King Ananda was found dead of gun wounds on June 9, 1946. Pridi was unjustly held responsible, in part because of his earlier radicalism and reputed republican sympathies, and in August he was forced to resign. When the army staged a coup d’état in November 1947, Pridi fled the country; by 1951, after coup attempts on his behalf had failed, he took up residence in China. In 1970 Pridi left China for France, continuing to voice his criticism of the Thai military regimes.