Icelanders enjoy freedom of religion under the constitution of Iceland, though the Church of Iceland, a Lutheran body, is the state church. The National Registry keeps account of the religious affiliation of every Icelandic citizen. In 2005, Icelanders were divided into religious groups as follows:
• 80.7% members of the National Church of Iceland.
• 6.2% members of unregistered religious organisations or with no specified religious affiliation.
• 4.9% members of the Free Lutheran Churches of Reykjavík and Hafnarfjörður.
• 2.8% not members of any religious group.
• 2.5% members of the Roman Catholic Church, which has a Diocese of Reykjavík (see also Bishop of Reykjavík (Catholic)).
The remaining 2.9% includes around 20–25 other Christian denominations while around 1% belong to non-Christian religious organisations. There is a small Muslim community of between 370 and 600, living mostly in Reykjavík, and about 30 – 50 Jews. The largest non-Christian denomination is Ásatrúarfélagið, a neopagan group. Many Icelanders, regardless of faith, retain some Norse folk beliefs. A survey measuring attitudes towards the supernatural found that around 40% of the population claimed to have had some kind of contact with the dead.
Iceland is a very secular country: as with other Nordic nations, religious attendance is relatively low. The above statistics represent administrative membership of religious organisations, which does not necessarily reflect the belief demographics of the population of Iceland. According to a study published in 2001, 23% of the inhabitants are either atheist or agnostic. A Gallup poll conducted in 2011 found that 60% of Icelanders considered religion to be unimportant in their daily lives, one of the highest rates of irreligion in the world
