The U.S. government estimates the total population at 8.4 million (midyear 2020 estimate). The population is predominantly Christian; Catholics are the largest denomination, followed by Protestants. According to census data, the number of persons with no religious affiliation has increased in the past decade as has the number of adherents to non-Christian faiths. According to Federal Statistics Office figures compiled in 2016-18 and issued in January, 35.8 percent of the population older than 15 is Roman Catholic, 23.8 percent is Reformed Evangelical, 7.4 percent belongs to other Christian groups, and 5.3 percent is Muslim. According to SIG, there are approximately 18,000 Jews. In October, media reported that the Jewish population had declined 10 percent since 1970, whereas the country’s total population had increased by 40 percent in the same time period. According to the gfs.bern polling and research institute, approximately 50 percent of Jewish households are located in Zurich, Geneva, Basel, Lausanne, and Lugano.

According to the Federal Statistics Office, persons identifying with no religious group constitute 26.3 percent of the population and the religious affiliation of 1.4 percent of the population is unknown. Of the population older than 15 belonging to other Christian groups, 2.5 percent is Orthodox Christian or Old-Oriental Christian and 2.2 percent is other Protestant, including evangelical, Pentecostal, and charismatic Christian. The remaining 1.4 percent includes Jehovah’s Witnesses, members of The Church of Jesus Christ of Latter-day Saints (Church of Jesus Christ), Seventh-day Adventists, and members of the Apostolic Church. The Christian Catholic Church estimates the number of Christian Catholics (also known as Old Catholics) at more than 12,000. Religious groups together constituting 1.4 percent of the population include Buddhists, Hindus, Baha’is, and Sikhs.

Approximately 95 percent of Muslims are of foreign origin from more than 30 countries. Media report most come from countries of the former Yugoslavia, predominantly from Kosovo, North Macedonia, Serbia, and Bosnia and Herzegovina, while others come from Albania, Turkey, North Africa, the Middle East, and sub-Saharan Africa. According to the most recent information available from reports issued in 2018 by local media and the University of Zurich, 75 percent of the Muslim community is Sunni, 15 percent Alevi, and approximately 10 percent Shia or other Muslim, including Ahmadi. According to the gfs.bern polling and research institute, approximately 80 percent of Muslims live in cities, with the largest populations in Zurich, Aarau, Bern, St. Gallen, Solothurn, Lausanne, and Geneva.