Icelandic nationality law details the conditions by which an individual is a national of Iceland. The primary law governing these requirements is the Icelandic Nationality Act, which came into force on 1 January 1953. Iceland is a member state of the European Free Trade Association (EFTA). All Icelandic nationals have automatic and permanent permission to live and work in any European Union (EU) or EFTA country.

Any person born within Iceland to at least one Icelandic parent receives citizenship at birth. Children born overseas are also Icelandic citizens if they are born to a married Icelandic parent, or to an unmarried Icelandic mother. Individuals born to an unmarried Icelandic father are eligible to acquire citizenship by registration before age 18. Foreign nationals may naturalise after meeting a minimum residence requirement (usually five years), proving financial self-sufficiency, demonstrating proficiency in the Icelandic language, and passing a good character requirement with supporting testimonials from two Icelandic citizens.