in late 20th-century Roman Catholicism, a movement centred in Latin America (Latin America, history of) that sought to apply religious faith by aiding the poor and oppressed through involvement in political and civic affairs. It stressed both heightened awareness of the socioeconomic structures that caused social inequities and active participation in changing those structures.

Liberation theologians believed that God speaks particularly through the poor and that the Bible can be understood only when seen from the perspective of the poor. They perceived that the Roman Catholic church in Latin America was fundamentally different from the church in Europe—i.e., that the church in Latin America was a church for and of the poor. In order to build this church, they established communidades de base, or base communities, local Christian groups composed of 10 to 30 members each, that both studied the Bible and attempted to meet their parishioners' immediate needs for food, water, sewage disposal, and electricity. A great number of base communities, led mostly by laypersons, sprang into being throughout Latin America.

The birth of the liberation theology movement is usually dated to the second Latin American Bishops' Conference, which was held in Medellín, Colom., in 1968. At this conference the attending bishops issued a document affirming the rights of the poor and asserting that industrialized nations enriched themselves at the expense of Third World countries. The movement's seminal text, Teología de la liberación (1971; A Theology of Liberation), was written by Gustavo Gutiérrez (Gutiérrez, Gustavo), a Peruvian priest and theologian. Other leaders of the movement included Archbishop Oscar Arnulfo Romero of El Salvador (killed in 1980), Brazilian theologian Leonardo Boff, Jesuit scholar Jon Sobrino, and Archbishop Helder Câmara of Brazil.

The liberation theology movement gained strength in Latin America during the 1970s. Because of their insistence that ministry includes involvement in the political struggle of the poor against wealthy elites, liberation theologians were often criticized—both formally, from within the Roman Catholic church, and informally—as naive purveyors of Marxism and advocates of left-wing social activism. By the 1990s the Vatican, under Pope John Paul II, had begun trying to curb the movement's influence through the appointment of more conservative prelates in Brazil and elsewhere in Latin America.