He was raised in Port-au-Prince and trained as a doctor, serving in rural areas. There he won acclaim for helping the poor fight typhus and other diseases. He married Simone Ovide in 1939, and became director general of the national health service in 1946. In 1949, he served as minister of both health and labour. After opposing the coup of Paul Magloire, he was forced into hiding until an amnesty in 1956.
Backed by the army, Duvalier won the 1957 Haitian elections; he had campaigned as a populist leader, attacking the "noirist" elite. Duvalier revived the traditions of vodun and later used them to consolidate his power, claiming to be a hougan himself. Duvalier deliberately modeled his image on that of Baron Samedi in an effort to make himself even more imposing.
He worked to consolidate his rule; after surviving a coup in mid-1958, he purged the army. He then rewrote the constitution and then won the 1961 election: the official count was 1.32 million votes for Duvalier and none against. He established himself as president for life in 1964 and his rule assumed a more brutal and repressive character. Wary of the army, he created a militia in 1959, known as the VSN (Volontaires de la Sécurité Nationale) from 1962, to protect his power outside the capital. The VSN became better known as the Tonton Macoute (or Makout). Because they received no official salary, they had to make their living through crime and extortion. To protect his person, Duvalier used the Garde Présidentielle.
Duvalier came under pressure from the government of John F. Kennedy due to evidence of corruption over aid. Aid was officially suspended in 1962 but the pressure eased following the death of Kennedy. The country assumed the mantle of an anti-communist presence to balance that of nearby Cuba.
In April 1963, Haiti was almost attacked by the Dominican Republic. Only the lack of senior military support for Juan Bosch Gaviño prevented the Dominicans invading; instead, the conflict was mediated by the OAS.
By the mid 60s it was clear Duvalier had no intention of stepping down. In June of 1964 he was proclaimed president for life and began to create a personality cult around the image of himself as the physical embodiment of the Haitian nation. Like some of his predecessors, Duvalier was often rumored to be contemplating making himself Emperor of Haiti, and ruling the nation as a monarch.
Within the country Duvalier used both political murder and expulsion to suppress his opponents; estimates of those killed are as high as 30,000. Attacks on Duvalier from within the military were treated as especially serious; in 1967 bombs detonated near the Presidential Palace led to the execution of twenty Garde Présidentielle officers.
His reign of terror kept the country in his grip until his death in early 1971, after he had set his 19-year-old son Jean-Claude Duvalier to succeed him.