Icelandic names are names used by people from Iceland. Icelandic surnames are different from most other naming systems in the modern Western world in that they are patronymic or occasionally matronymic: they indicate the father (or mother) of the child and not the historic family lineage. Iceland shares a common cultural heritage with the Nordic countries of Denmark, the Faroe Islands, Norway, Sweden and Finland. Unlike other Nordics, Icelanders have continued to use their traditional name system, which was formerly used by all Nordic countries. The Icelandic system is thus not based on family names (although some people do have family names and might use both systems). Generally, with few exceptions, a person's last name indicates the first name of their father (patronymic) or in some cases mother (matronymic) in the genitive, followed by ("son") or ("daughter").
Some family names do exist in Iceland, most commonly adaptations from last names Icelanders took up when living abroad, usually in Denmark. Notable Icelanders who have an inherited family name include former prime minister Geir Haarde, football star Eiður Smári Guðjohnsen, entrepreneur Magnús Scheving, film director Baltasar Kormákur Samper, and actress Anita Briem. Before 1925, it was lawful to adopt new family names; one Icelander to do so was the Nobel Prize-winning author Halldór Laxness, while another author, Einar Hjörleifsson and his brothers all chose the family name "Kvaran". Since 1925, one cannot adopt a family name unless one explicitly has a legal right to do so through inheritance.
First names not previously used in Iceland must be approved by the Icelandic Naming Committee before being used. The criterion for acceptance of names is whether they can be easily incorporated into the Icelandic language. With some exceptions, they must contain only letters found in the Icelandic alphabet (including þ and ð), and it must be possible to decline the name according to the language's grammatical case system, which in practice means that a genitive form can be constructed in accordance with Icelandic rules. Names considered to be gender-nonconforming have historically not been allowed; however, in January 2013, a 15-year-old girl named Blær (a masculine noun in Icelandic) was allowed to keep this name in a court decision that overruled an initial rejection by the naming committee. Her mother Björk Eiðsdóttir did not realize at the time that Blær was considered masculine; she had read a novel by Halldór Laxness, The Fish Can Sing (1957), that had an admirable female character named Blær, meaning "light breeze", and had decided that if she had a daughter, she would name her Blær.
In 2019, the laws governing names were changed. First names are no longer restricted by gender. Moreover, Icelanders who are officially registered as non-binary will be permitted to use the patro/matronymic suffix ("child of") instead of or .
Typical Icelandic naming
A man named Jón Einarsson has a son named Ólafur. Ólafur's last name will not be Einarsson like his father's; it will become Jónsson, indicating that Ólafur is the son of Jón (Jóns + son). The same practice is used for daughters. Jón Einarsson's daughter Sigríður'''s last name would not be Einarsson but Jónsdóttir. Again, the name means "Jón's daughter" (Jóns + dóttir).
In some cases, an individual's surname is derived from a parent's second given name instead of the first. For example, if Jón is the son of Hjálmar Arnar Vilhjálmsson, he may either be named Jón Hjálmarsson (Jón, son of Hjálmar) or Jón Arnarsson (Jón, son of Arnar). The reason for this may be that the parent prefers to be called by the second given name instead of the first; this is fairly common. It may also be that the parent's second name seems to fit the child's first name better.
In cases where two people in the same social circle bear the same first name and the same father's name, they have traditionally been distinguished by their paternal grandfather's name (avonymic), e.g. Jón Þórsson Bjarnasonar (Jón, son of Þór, son of Bjarni) and Jón Þórsson Hallssonar (Jón, son of Þór, son of Hallur). This practice has become less common (the use of middle names having replaced it), but features conspicuously in the Icelandic sagas.
Matronymic naming as a choice
The vast majority of Icelandic last names carry the name of the father, but occasionally the mother's name is used: e.g. if the child or mother wishes to end social ties with the father. Some women use it as a social statement while others simply choose it as a matter of style.