Bidault was born in Moulins, Allier. He studied in the Sorbonne and became a college history Teacher. In 1932 he helped to found the Catholic Association of French Youth and the left-wing anti-fascist newspaper l'Aube. He had a column in the paper and, among other things, protested against the Munich Agreement in 1938.

After the outbreak of the Second World War he joined the French army. He was captured during the Fall of France and was briefly imprisoned. After his release in July 1941, he became a Teacher at the Lycée du Parc in Lyon and joined the Liberté group of French Resistance that eventually merged with Combat. Jean Moulin recruited him to organize an underground press and the Combat underground newspaper.

Bidault participated in the forming of the Conseil National de la Résistance and, after the Gestapo captured Moulin, he became its new chairman. In 1944 he formed a Resistance Charter that recommended an extensive post-war reform program. After the liberation of Paris he represented the Resistance in the victory parade. Charles de Gaulle appointed him as a foreign minister of his provisional government on 25 August. He was the founder of the Mouvement Républicain Populaire (MRP).

He was head of the French delegation to the San Francisco Conference, which established the UN, from April to June 1945. At the conference, France succeeded in gaining a permanent seat on the Security Council.

On 4 January 1946, Bidault married Suzanne Borel, the first French woman to be employed as a diplomat. The same year he served as foreign minister in Félix Gouin's provisional government. On 19 June 1946 the National Constituent Assembly elected him as President of the provisional government. His government, formed on 15 June, was composed of socialists, communists and Bidault's own MRP. In social policy, Bidault's government was notable for passing important pension and workman’s compensation laws. An act of 22 August 1946 extended coverage of family allowances to practically the entire population, while a law of October 1946 provided that insurance of occupation risks "would henceforth be mandatory and that such insurance would be granted by the Social Security that had been created in 1945." In August 1946, an Act was passed that made provision for two day’s holiday a month up to a maximum of 24 working days for young persons between the ages of 14 and 18 and for one-and-a-half days' a month up to a maximum of 18 working days for those aged between 18 and 21. In addition, an Act was passed on 11 October 1946 that introduced occupational medical services.

Bidault served in various French governments, first as foreign minister under Paul Ramadier and Robert Schuman. In April 1947 he supported Ramadier's decision to expel the Communists from his government. Bidault had recently been to Moscow and was disturbed by the Soviet regime; he believed an agreement with Stalin was impossible.

In 1949 he became the President of the Council of Ministers (prime minister) but his government lasted only 8 months. During his last term as prime minister, a law of February 1950 that regulated collective bargaining, and contained a guarantee of the right of workers to strike. The same law required the government to fix minimum wages for agriculture and for industry. In Henri Queuille's governments in 1950–1951 he held the office of Vice-president of the Council and under Rene Pleven and Edgar Faure also the post of defense minister.

In 1952 Bidault became an honorary President of MRP. On 1 June 1953 President Vincent Auriol assigned him to form his own government but the National Assembly refused to give him the official mandate at 10 June. In 1953 Bidault became a presidential candidate but withdrew after the second round.

Bidault was foreign minister during the siege of the French garrison at Dien Bien Phu from March to May 1954. He protested to the Red Cross that the Viet Minh were shooting at clearly marked French medical evacuation flights, killing some of the evacuees. The ongoing fighting in Indochina had exhausted him; he was described by American secretary of state John Foster Dulles as "a deeply harassed man" and later by a Historian as "on the verge of a nervous breakdown". Caught between his desires to end the war and to maintain the integrity of France's colonies, he vacillated between pressing the war, perhaps by asking the Americans for air support, or seeking a negotiated solution. Bidault stated that John Foster Dulles (then Secretary of State of United States) offered France two atomic bombs in 1954.

In April 1958 Bidault again became prime minister but did not form a cabinet and had a hand in forming the conservative Christian Democratic Movement. He also supported De Gaulle's presidency after the outbreak of the Algerian War of Independence.

In 1961 Bidault became President of the Executive Council of the Rally for French Algeria and opposed De Gaulle's policy of Algerian independence. He established his own National Resistance Council within the far-right paramilitary organization OAS (Organisation armée secrète). In June 1962 he was accused of conspiring against the state and stripped of his parliamentary immunity. He left for exile in Brazil. In 1967 he moved to Belgium and in 1968 returned to France after benefiting from an amnesty.

When the Front national was founded in October 1972 by members of Ordre nouveau, he participated but resigned from the organisation a few days later.

Bidault died of a stroke in Cambo-les-Bains in January 1983.