Religion in Iceland

Religion in Iceland has been predominantly Christianity since its adoption as the state religion by the Althing under the influence of Olaf Tryggvason, the king of Norway, in 999/1000 CE. Until then, in the 9th and 10th centuries, the prevailing religion among the early Icelanders — who were mostly Norwegian settlers fleeing Harald Fairhair's monarchical centralisation in 872–930, with some Swedes and Norse British settlers — was the northern Germanic religion, which persisted for centuries even after the official Christianisation of the state.

Starting in the 1530s, Iceland, originally Roman Catholic and under the Danish crown, formally switched to Lutheranism with the Icelandic Reformation, which culminated in 1550.^[2] The Lutheran Church of Iceland has since then remained the country's state church.^[2] Freedom of religion has been granted to Icelandic citizens since 1874; the Church of Iceland is supported by the government, but all religions officially recognised in the state's civil registry receive support from a church tax (sóknargjald) owed by their respective populations of adherents over the age of sixteen, who are counted by the state's statistical office on a yearly basis; citizens who declare that they are not affiliated with any religion owe an equivalent tax to the University of Iceland.^[3]

Since the late 20th century, and especially in the early 21st century, religious life in Iceland has become more diverse, with a decline in the main forms of Christianity, the rise of unaffiliated people, and the emergence of new religions, notably Germanic Heathenism (or Heathenry; Germanic Neopaganism) in Iceland also called Ásatrú, which seeks to reconstruct the Germanic folk religion; a secular grouping of Humanism; Buddhism; Islam; Mesopotamian Zuism (Mesopotamian Neopaganism); and others.^[1]

As of 2023, Christians constituted 69.55% of the Icelandic population, a marked decline from the 97.8% observed in 1990 according to Statistics Iceland. Within the Christian category, 58.61% identified as Lutherans belonging to the Church of Iceland. This is a significant decrease from the 92.6% who identified this way in 1990. Other minor Lutheran free churches accounted for 5.33%, Roman Catholicism for 3.83%, and other Christian denominations for 1.78%.^[1] The Roman Catholic community has grown from 0.9% in 1990, and other Christian denominations saw growth mainly between 1990 and the 2010s, stabilizing thereafter.^[1][4]

The data for 2023 also indicate an increase in non-Christian religious affiliations and in those who identify as non-religious. Heathenry, a polytheistic religion native to Iceland, accounted for 1.5% of the population. Humanists made up 1.39%, Buddhists 0.42%, and Muslims 0.40%. Zuists and adherents to other religions represented 0.14% and 0.16%, respectively.^[1][4]

A growing segment of the population—18.73% as of 2023—adheres to religions, philosophies, or life stances not recognized in the civil registry, or did not declare any religious affiliation. This category has seen a substantial increase from 0.6% in 1990 and has tripled from 6.2% in 2010. Meanwhile, the percentage of Icelanders who declared themselves explicitly unaffiliated with any religion, philosophy, or life stance was 7.71% in 2023, up from 1.3% in 1990.^[1][4]