Roman Catholicism is by far the largest religion in the country. Although the Catholic church has never been the state religion, it still plays a role in the nation's political affairs, partly due to the Holy See's location in Rome. 87.8% of Italians identified as Roman Catholic although only about one-third of these described themselves as active member (36.8%).

Other Christian groups in Italy include 500,000 Jehovah's Witnesses (0.9%) , more than 700,000 Eastern Orthodox Christians (1.2%) , including 470,000 newcomers and some 180,000 Greek Orthodoxes , 450,000 Pentecotalists and Evangelicals (0.8%), of which 300,000 members of the Assemblies of God , 30,000 Waldensians , 25,000 Seventh-day Adventists , 22,000 Mormons , 15,000 Baptists (plus some 5,000 Free Baptists), 7,000 Lutherans , 5,000 Methodists (affiliated to the Waldensian Church).