The Catholic Church in Chile is part of the worldwide Catholic Church, under the spiritual leadership of the Pope, the curia in Rome, and the Episcopal Conference of Chile.

The Church is composed of 5 archdioceses, 18 dioceses, 2 territorial prelatures, 1 apostolic vicariate, 1 military ordinariate and a personal prelature (Opus Dei). The government observes the following Catholic Holy Days as national holidays (if on a week day): Good Friday, Christmas, Feast of the Virgin of Carmen, the Feast of the Immaculate Conception, the Feast of Saints Peter and Paul, the Feast of the Assumption, and All Saints Day.

The Catholic Church in Chile has had a complex relationship with the Chilean state, particularly during the latter half of the 20th century, with the government of Salvador Allende and the dictatorship of Augusto Pinochet. The influence of liberation theology and political ideologies also contributed to internal disagreements and changing Church attitudes.

In 2024, 54% of the Chilean population self-identified as Catholic in the census; last time religion was considered in the census, in 2002, it was 70% of the population. A report in 2021 indicated that this number had declined to 42%. The Catholic Church sexual abuse cases in Chile, especially the Karadima case which came to light in 2010 and led to Karadima's conviction in 2011, had a negative influence on Chilean public opinion of the Church. Chilean trust in the Catholic Church plummeted from 61% in 2010 to 38% in 2011, and 36% in 2017; the lowest of any Latin American country.

Catholicism was introduced by Dominican and Franciscan friars who accompanied the Spanish colonialists in the 16th century. The first parish was established in 1547 and the first diocese in 1561. Most of the native population in the northern and central regions was evangelized by 1650. The southern area proved more difficult. Church activity was hindered during the campaign for independence (1810–18) and in the first years of the new government. In the 20th century, further success was impeded by a shortage of clergy and government attempts to control Church administration. Separation of Church and state was established by a new constitution in 1925.

Relations between Church and state were complicated during the Socialist presidency of Salvador Allende (November 1970 − September 1973). While Allende and the state refrained from attacking the Church, the majority of the Catholic hierarchs in Chile were either ideologically opposed to Allende and his socialist program or cautious of open clerical involvement in politics. However, a vocal minority of priests, followers and participants of liberation theology, were supporters of the government. On April 16, 1971, a group of these priests, "The 80", released a declaration advocating for Catholics to actively participate in Allende's cause and the socialist program.

The 80 would subsequently form the organization Christians for Socialism. Other Catholic organizations were also a part of Allende's Popular Unity coalition, including the Christian Left and MAPU, which split off from the more centrist Christian Democratic Party. Previously, Catholic involvement in Chilean politics had been represented primarily by the Christian Democratic Party, which as a political organization was institutionally separate from the Church. In 1972, twelve members of Christians for Socialism were invited to visit Cuba by Fidel Castro, while there they spoke in support of socialist revolution. In April of that year, Christians for Socialism held a First Latin American Congress of Christians for Socialism in the city of Santiago; its focus was reflection on the activities of Christians who practiced liberation theology in Latin America. It was attended by laypeople, clergy, and a single hierarch, Mexican bishop Sergio Méndez Arceo. The Archbishop of Santiago, Cardinal Raúl Silva Henríquez, was invited but turned down the invitation because he believed Christians for Socialism was trying to push the Church into supporting communist revolution. In April, following the conference, the Chilean bishops issued two statements, one rebuking the statement of the twelve who went to Cuba, and the other treading a middle ground between respect for Allende and affirming his legitimacy, while maintaining a nominally apolitical stance and that Marxism was inconsistent with Catholicism.

During the Allende administration and immediately preceding it, supportive elements of the Chilean Catholic Church did not limit themselves to declarations of solidarity with the poor or the government—they also performed it through material acts. During this time, some nuns and priests were already living and working with the poor (as a result of evangelization efforts undertaken by the Church to address the widespread lack of clergy across Latin America or through their own volition) in order to better serve the people and understand their reality; one example took the form of Father Ignacio Pujadas, who formed a Christian Base Community in his neighborhood and was later a founding member of Christians for Socialism. Other groups of organizations such as Catholic Action and the Catholic Student Youth were already working towards similar goals as Christians for Socialism. Parts of the Church also voluntarily aided the Allende government: in 1971, the Society of the Sacred Heart gave the Chilean government some of its private high schools, and the Congregation of the Holy Cross raised tuition for rich students in their Santiago school to fund scholarships for poor students, both in accordance with Allende's project of increasing educational access.