Catholic schools are parochial pre-primary, primary and secondary educational institutions administered in association with the Catholic Church. As of 2011^[update], the Catholic Church operates the world's largest religious, non-governmental school system. In 2016, the church supported 43,800 secondary schools and 95,200 primary schools. The schools include religious education alongside secular subjects in their curriculum.

Across Europe, North America, Australia and New Zealand, a major historical driver for the establishment of Catholic schools was Irish immigration. Historically, the establishment of Catholic schools in Europe encountered various struggles following the creation of the Church of England in the Elizabethan Religious settlements of 1558–63. Anti-Catholicism in this period encouraged Catholics to create modern Catholic education systems to preserve their traditions. The Roman Catholic Relief Act 1782 (21 & 22 Geo. 3. c. 24 (I)) and the Catholic Emancipation Act 1829 later increased the possibility to practice Catholic Christianity in England openly and to create charitable institutions by the Church. This led to the development of numerous native religious congregations which established schools, hospitals, orphanages, reformatories, and workhouses.

Catholic schools are distinct from their public school counterparts in focusing on the development of individuals as practitioners of the Christian faith. The leaders, teachers, and students must focus on four fundamental rules initiated by the Church and school. This includes the Catholic identity of the school, education in regards to life and faith, the celebration of life and faith, and action and social equality.

Like other Christian-affiliated institutions, Catholic schools are generally nondenominational, in that they accept anyone regardless of religion or denominational affiliation, sex, race or ethnicity, or nationality, provided the admission or enrollment requirements and legal documents are submitted, and rules and regulations are obeyed for a fruitful school life. However, non-Catholics, whether Christian or not, may need to participate in or be exempted from required activities, particularly those of a religious nature. These are in keeping with the spirit of social inclusiveness.

The religious education as a core subject is a vital element of the curriculum where individuals are to develop themselves: "intellectually, physically, socially, emotionally and of course, spiritually." The education also involves: "the distinct but complementary aspect of the school's religious dimension of liturgical and prayer life of the school community." In Catholic schools, teachers teach a Religious Education Program provided by the Bishop and Superintendent. The teacher Pastor, and Bishop therefore, contribute to the planning and teaching Religious Education Lessons.^{[citation needed]}

Catholic education has been identified as a positive fertility factor; Catholic education at the college level and, to a lesser degree, at secondary school level is associated with a higher number of children, even when accounting for the confounding effect that higher religiosity leads to a higher probability of attending religious education.

The existence of Catholic schools in Canada can be traced to the year 1620, when the first school was founded by the Catholic Recollet Order in Quebec. Most schools in Canada were operated under the auspices of one Christian body or another until the 19th century. Currently publicly supported Catholic schools operate in three provinces (Alberta, Ontario, and Saskatchewan), as well as all three federal territories (Northwest Territories, Nunavut, and Yukon [to grade 9 only]). Publicly funded Catholic schools operate as separate schools in Canada, meaning they are constitutionally protected. The constitutional protection enjoyed by separate schools in Canadian provinces is enshrined in Section 93 of the Constitution. It gives provinces power over education but with restrictions designed to protect minority religious rights. These restrictions resulted from the significant debate between Protestants and Catholics in Canada over whether schools should be parochial or nondenominational. As opposed to the provinces, the right to separate schools is protected in the three federal territories by the federal Acts of Parliament, which establish those territories.

Section 93 was the result of constitutional negotiations in the 1860s. Pre-existing rights for tax-funded minority Catholic and Protestant schools had become a significant point for negotiations surrounding Canadian Confederation. Retention of separate school boards with public funding was a significant issue, chiefly due to ethnic and religious tension between Canada's (primarily French-speaking) Catholic population and the (primarily English-speaking) Protestant majority. The issue was a subject of debate at the 1864 Quebec Conference. It was finally resolved at the London Conference of 1866 with a proposal to preserve the separate school systems in Quebec and Ontario. The agreement was written into the Constitution to the effect that the condition of education in each colony (or territory) when it entered Confederation would be constitutionally protected after that.