The Popular Republican Movement (French: Mouvement Républicain Populaire, MRP) was a Christian-democratic political party in France during the Fourth Republic. Its base was the Catholic vote and its leaders included Georges Bidault, Robert Schuman, Paul Coste-Floret, Pierre-Henri Teitgen and Pierre Pflimlin. It played a major role in forming governing coalitions, in emphasizing compromise and the middle ground, and in protecting against a return to extremism and political violence. It played an even more central role in foreign policy, having charge of the Foreign Office for ten years and launching plans for the creation of the European Coal and Steel Community, which grew into the European Union. Its voter base gradually dwindled in the 1950s and it had little power by 1954.

In the late 19th century secular forces sought to radically reduce the power of the Catholic Church in France, especially regarding schools. The Catholic bishops mistrusted the Republic and the ideas of the French Revolution, as well as the idea of popular sovereignty, which questioned the superiority of the spiritual power over the temporal. For this reason, it supported all the conservative governments of the 19th century, notably MacMahon and his policy of "moral order".

In 1892, in his encyclical Au Milieu Des Sollicitudes, Pope Leo XIII advised the French Catholics to rally to the Republic. The previous year, another encyclical, Rerum novarum had denounced both capitalistic society and socialist ideology, and advocated the creation of Catholic popular organisations. In 1894, students founded Le Sillon (The Furrow). Its leader, Marc Sangnier, campaigned for spiritual values, democracy and social reforms. It represented the progressive wing of French Catholicism. Radical forces triumphed in 1905 and disestablished the Catholic Church and seized its properties. The very conservative Pope Pius X told the bishops to distance themselves from the state and condemned Le Sillon in his 1910 encyclical Notre charge apostolique. Better relations were restored in the 1920s, but the parties on the left (Radical, Socialist and Communist) were strongly anticlerical.

At the beginning of the 20th century, many organisations appeared: the Christian Workers Youth, the Christian Agricultural Youth, and the French Confederation of Christian Workers. In 1924, the Popular Democratic Party (PDP) was founded, but it remained a small centre-right party. However, more liberal Christian Democratic ideas arose in intellectual circles. Emmanuel Mounier founded the review Esprit (mind or spirit) which denounced fascism and passivity of the Western democracies. In the paper L'Aube (The Dawn), Francisque Gay and Georges Bidault shared similar theses. These circles participated actively in the anti-Nazi underground Resistance during the Second World War.

In 1944, some prominent French politicians wanted to rally all the non-Communist Resistance behind Charles De Gaulle. This project failed. The French Section of the Workers' International (SFIO) was refounded and people from the Christian resistance movement founded the Popular Republican Movement. It claimed its loyalty to de Gaulle, who led the provisional government composed of Communists, Socialists and Christian democrats. At the November 1945 legislative election, the MRP was second (23.9%) after the French Communist Party (PCF) but ahead the SFIO.

The MRP benefited from the absence of real right-wing challengers to rally the conservative electorate. Indeed, among the three largest parties, it was the only one that was not Marxist. Furthermore, it appeared the closest to de Gaulle. It supported the reforms decided by the provisional government and inspired by the programme of the National Council of Resistance written during the war: nationalisation of banks and industrial companies such as Renault, and the creation of a welfare state. Georges Bidault remarked that the MRP was governing "in the centre with right-wing methods to attain left-wing ends" or that it was "pursuing left-wing policies with a right-wing electorate" (une politique de gauche, avec un électorat de droite).

Nevertheless, the MRP disagreed with the institutional and constitutional ideas of De Gaulle, who advocated a strong executive power, not dependent on Parliament, acting in the national interest while particular interests would be represented by the parties in Parliament. Wanting to achieve the complete integration of Catholicism in the Republic, the MRP supported the principle of parliamentary democracy against De Gaulle.

Relations with De Gaulle deteriorated. In January 1946, the president of the provisional government resigned in protest at the restoration of the "parties regime". The MRP ministers chose to stay in government. Nevertheless, the party called on voters to reject the proposed constitution in May 1946, fearing the election of a pro-Communist regime. After that, the MRP became the largest party in parliament after the June 1946 legislative election (28.2%) and Bidault took charge of the cabinet. In October 1946, the MRP, together with the SFIO and the PCF, presented a new proposed constitution. It was approved despite De Gaulle's call for a "no" vote. One year later, a Gaullist party was founded under the name of Rally of the French People (Rassemblement du peuple français or RPF).