For centuries, Catholicism was the dominant form of Christianity in Switzerland. However, the Reformation brought about a significant shift in the population's religious identity. Today, members of the Roman Catholic Church and the Protestant Reformed Church remain the largest denominational groups in the country.

Spread of Christianity

Christianity began to spread in Switzerland from the 4th century onwards, facilitated by the structures of the Roman Empire. Bishoprics were established and amassed large estates, exerting influence over both agricultural practices and political affairs. In the 7th century, monasteries were founded and evolved into significant hubs of education and cultural development. Starting from the 13th century, the power of the church gradually diminished, especially during the Reformation and later with the implementation of the Swiss Federal Constitution, which prohibited clergy from participating in political life for an extended period.

In modern Switzerland, Christianity is primarily represented by two large, well-established national churches: the Roman Catholic Church and the Protestant Reformed Church. As recently as 1970, an overwhelming 98% of the Swiss population was affiliated with various Christian churches. Since then, the Roman Catholic Church has maintained a relatively stable membership, largely due to immigration from southern Europe. In contrast, the Protestant Reformed Church has experienced a sharp decline in membership. More and more people in Switzerland do not identify with any specific religion.

Catholicism

The Catholic Church wielded great power in Switzerland during the Middle Ages until the Reformation greatly reduced its influence. However, the Catholic Church experienced a revival through the Counter-Reformation, with the Jesuits establishing a Catholic education system and the Capuchins providing pastoral care. The Abbey Library and Abbey Archives from this period, located at the Monastery Complex of St Gallen, are now recognised as a UNESCO World Heritage Site.

Shaped by historical events, political changes, and modern influences, the Catholic Church has evolved into a stable and diverse religious community that maintains its influence in certain regions. More than a third of the Swiss population belongs to the Catholic Church, making it the country's largest religious denomination. The cantons with the highest proportion of Catholics are Uri, Valais, Obwalden and Appenzell-Innerrhoden. The Roman Catholic Church in Switzerland is divided into six dioceses, with seats in Solothurn, Fribourg, Sion, Chur, St Gallen, and Lugano. The bishops of these dioceses report directly to the Pope.

Protestantism

At the start of the 16th century, the Swiss population in both cities and rural areas demanded greater autonomy and participation in public affairs. Protestant reformers Huldrych Zwingli in Zurich and Jean Calvin in Geneva aided secular officeholders in freeing themselves from the authority of Catholic bishops. The Protestant Reformation, particularly Calvinism, spread rapidly throughout Europe, with Switzerland being a major centre. Protestantism places great emphasis on rationalism and hard work. The stipulation that all believers must be able to understand the Bible led to universal literacy, including of women, and thus to a general increase in the level of education. The Protestant ethic has had a decisive influence on Swiss identity and despite conflicts and tensions, the Protestant Reformation ultimately strengthened relations between the different regions of Switzerland.

Today, the Protestant Reformed Church accounts for one-fifth of the Swiss population, with a majority in the cantons of Bern, Appenzell-Ausserrhoden and Schaffhausen.

The Protestant Reformed churches are organised on a cantonal basis, each led by a synod and a synodal council. Together with a number of free churches, they form the Swiss Protestant Reformed Church.