The oldest known of Italy's Protestant churches, the Waldensian Evangelical Church, is a pre-Lutheran Protestant denomination, which was founded by Peter Waldo in the 12th century and, after the Protestant Reformation, adhered to Calvinist theology and became the Italian branch of the Reformed churches. The church's heartland is a cluster of Alpine valleys, the so-called "Waldensian Valleys" (Val Pellice, Val Chisone and Valle Germanasca), in western Piedmont. Since 1975 the Waldensians form a united church with the Methodist Evangelical Church in Italy.^[4] The ideas of Girolamo Savonarola also had spread around Florence around the 15th century.^[5]

The Reformation in Italy began at the end of the 15th century and quickly collapsed at the beginning of the 17th century. Its development was hindered by stern repression by the Inquisition of the Catholic Church.^[6] Groups of Italian Protestants had more comfortable lives in Switzerland, particularly in the Graubünden region.

On 17 February 1848 Charles Albert, king of Piedmont-Sardinia, granted religious freedom and civic emancipation to the Waldensians. Freedom of worship and equality of civic and political rights were later extended to Jews and to the other Italian states that were progressively annexed to Piedmont-Sardinia during the process of unification of Italy. Newer Waldensian congregations sprang up as well as the Free Christian Church^[7] (which lasted from 1852 to 1904) and the Evangelical Christian Church of the Brethren.^[8][9] Meanwhile British and American missionaries began to preach and establish Anglican, Methodist and Baptist churches.

In the early 20th century, missionaries spread the Pentecostal gospel throughout the country. Nowadays, most of those resulting Pentecostal congregations belong to the Assemblies of God in Italy, the Federation of Pentecostal Churches, and the Apostolic Church in Italy.

The Federation of Evangelical Churches in Italy (FCEI), formed in 1967, comprises all the historical Protestant churches of Italy (including the Union of Methodist and Waldensian Churches, the Lutheran Evangelical Church in Italy, the Baptist Evangelical Christian Union of Italy, and some minor churches), plus two observer members with a large following (the Federation of Pentecostal Churches and the Italian Union of Seventh-day Adventist Christian Churches).^[10][11]

Protestantism, especially in its Pentecostal forms, is thus on the rise. The Assemblies of God have the majority of their communities in the South^[12] and, according to Caritas Italiana, in 2012 the North of Italy was home to 850 "African Neo-Pentecostal churches".^[13]

• Religion in Italy
• Christianity in Italy
• Catholic Church in Italy
• List of Italian religious minority politicians
• Conference of Protestant Churches in Latin Countries of Europe
• Waldensians
• Waldensian Evangelical Church
• Peter Martyr Vermigli