French politician, twice premier of the Fourth Republic (1950–51, 1951–52), who is best known for his sponsorship of the Pleven Plan for a unified European army. His efforts spurred the creation of the North Atlantic Treaty Organization (NATO).

After receiving a law degree from the University of Paris, Pleven became an industrial executive. During World War II, he joined General Charles de Gaulle's (Gaulle, Charles de) Free French government, serving successively as commissioner of finance, colonies, and foreign affairs and becoming colonial minister in 1944. After the liberation of France he became minister of finance in de Gaulle's Cabinet and in 1945 was elected deputy to the National Assembly. From 1946 to 1953 he was president of the left-centre Democratic and Socialist Union of the Resistance (Union Démocratique et Socialiste de la Résistance; UDSR); he was twice minister of defense (1949–50, 1952–54) and twice premier (July 1950–February 1951 and August 1951–January 1952).

Pro-American in outlook, Pleven convened a conference in Paris in July 1950 to draw up a plan for a European army, the European Defense Community, to unify North Atlantic and western European defense under a single high command. Although the plan was opposed by the French Communists, Socialists, and Gaullists, and none of the governments to which Pleven belonged was willing to ratify the necessary treaty, he had helped lay the foundations of NATO. In Indochina he carried on the war against the nationalist Viet Minh with American aid.

Pleven quit the UDSR in 1958 to support de Gaulle's new constitution and the Fifth Republic. He formed a new party, the Union for a Modern Democracy, in 1959. In 1966 he criticized de Gaulle for withdrawing France from NATO, but he supported the Gaullist government after de Gaulle's resignation in April 1969. He was minister of justice (1969–73) and president of the council of Brittany (1974–76).