Action Française (French pronunciation: [aksjɔ̃ fʁɑ̃sɛːz], AF; English: French Action) is a French far-right monarchist and nationalist political movement. The name was also given to a journal associated with the movement, L'Action Française, sold by its own youth organization, the Camelots du Roi.

The movement and the journal were founded by Maurice Pujo and Henri Vaugeois in 1899, as a nationalist reaction against the intervention of left-wing intellectuals on behalf of Alfred Dreyfus. The royalist militant Charles Maurras quickly joined Action Française and became its principal ideologist. Under the influence of Maurras, Action Française became royalist, counter-revolutionary (objecting to the legacy of the French Revolution), anti-parliamentary, and pro-decentralization, espousing corporatism, integralism, and Roman Catholicism.

Shortly after it was created, Action Française tried to influence the public opinion by turning its journal into a daily newspaper and by setting up other organizations. It was at its most prominent during the 1899–1914 period. In the interwar period, the movement still enjoyed some prestige from support among conservative elites, but its popularity gradually declined as a result of the rise of fascism in Europe and of a rupture in its relations with the Catholic Church. During the Second World War, Action Française supported the Vichy Regime and Marshal Philippe Pétain. After the fall of the Vichy Regime, its newspaper was banned and Maurras was sentenced to life imprisonment in 1944, although he was reprieved in 1952.

The movement nevertheless continued in new publications and political associations, although with fading relevance as monarchism lost popularity, and French far-right movements shifted toward an emphasis on Catholic values and defense of traditional French culture. It is seen by some as one progenitor of the current National Rally political party.

The ideology of Action Française was dominated by the precepts of Charles Maurras, following his adherence and his conversion of the movement's founders to monarchism. The movement supported a restoration of the House of Bourbon-Orléans and, after the 1905 law on the separation of Church and State, the restoration of Roman Catholicism as the state religion, all as rallying points in distinction to the Third Republic of France which was considered corrupt and atheistic by many of its opponents.

The movement advocated decentralization (a "federal monarchy"), with the restoration of pre-Revolutionary liberties to the ancient provinces of France (replaced during the Revolution by the departmental system). It aimed to achieve a restoration by means of a coup d'état, probably involving a transitional authoritarian government.

Action Française was not focused on denouncing one social or political group as the conspiratorial source of ills befalling France. Different groups of the French far-right had animuses against Jews, Huguenots (French Calvinists), and Freemasons. To these, Maurras added unspecific foreigners residing in France, who had been outside French law under the Ancien Régime, and to whom he invented a slur name derived from ancient Greek history: métèques. These four groups of "internal foreigners" Maurras called les quatre états confédérés and were all considered to be part of "anti-France". He also opposed Marxism and the October Revolution, but antagonism against them did not have to be manufactured.

In 1899, Maurice Pujo and Henri Vaugeois left the French nationalist movement Ligue de la Patrie française and established a new one, called Action Française, and its official journal, Revue de l'Action Française. This was their nationalist reaction against the intervention of left-wing intellectuals on the behalf of Alfred Dreyfus.