Snorri Thorfinnsson (Old Norse and Icelandic: Snorri Þorfinnsson or Snorri Karlsefnisson) probably born between 1004 and 1013, and died c. 1090) was the son of explorers Þorfinnur Karlsefni and Guðríður Þorbjarnardóttir. He is considered to be the first white child to be born in the Americas, apart from Greenland. He became an important figure in the Christianisation of Iceland.
Snorri is an Old Norse name derived from the word snerra, meaning "a fight." Þorfinnsson is a patronymic, meaning "son of Þorfinnr", (see Icelandic naming conventions). Snorri was named for his great-grandfather, Snorri Þórðarson, or after Snorri Þorbrandsson who was not a kinsman but a participant in Karsefni's expedition
There is speculation about the birth date of Snorri Thorfinnsson. Birth years such as 1005, 1009, and 1012 have been postulated, but all sources agree that he was born between 1005 and 1013. According to the Vinland sagas, when Snorri was 3 years old, his family left Vinland because of hostilities with indigenous peoples (called Skrælingar by the settlers, meaning "barbarians"). The family returned to the Glaumbær farm in Seyluhreppur. 
Snorri Thorfinnsson had two children; a daughter named Hallfrid, and a son named Thorgeir. Hallfrid was the mother of Thorlak Runolfsson, bishop of Skálholt in the south of Iceland. One of the descendants of Snorri's brother Thorbjorn, Bjorn Gilsson, was also a bishop of Hólar. Thorgeir was the father of Yngvild who was the mother of Brand Sæmundarsson, bishop of Hólar. The sculptor Bertel Thorvaldsen claimed descent from Snorri Thorfinnsson in the 19th century.
Christianisation of Iceland
In the 13th century texts Snorri Thorfinnsson and Snorri Thorrgrimsson are considered the two main figures responsible for the early Christianisation of Iceland. Consequently, they were portrayed by various writers of the 13th and 14th century as "Christian chieftain models". According to Grœnlendinga saga, Snorri had built the first church of Glaumbaer, which would later increase Christian influence in the area. His descendants became the first Bishops of Iceland, and published the first Christian Code of Iceland.
- Snorri Thorfinnsson was purported to be born in Vinland, (America), making him the first European known to be born in the Americas, provided that Greenland is defined as being outside the Americas.
- In 2002 American archaeologists discovered the remains of a thousand-year-old longhouse located on Iceland's northern coast. It is believed that it was Snorri Thorfinnsson's farmhouse. The longhouse was found near the Glaumbaer Folk Museum, at the Skagafjordur Heritage Museum outside the coastal village of Sauðárkrókur. The museum was once thought to have been built on the site of Snorri's farmhouse. According to archaeologists it was "a classic Germanic fortress longhouse like the Great Hall of Beowulf".
- There is a non-profit organisation called The Snorri Program, that focuses on the history of Icelandic settlers in North America and regularly runs exchange programs for youth and adults. 
Below is the genealogy of descendants of Snorri, as given in the close of each saga, Grœnlendinga saga ch. 9 and Eiríks saga ch. 14. It is supplemented with further ancestral information from (Eiríks saga ch. 7 and Landnámabók), a more complete family tree for which, see Thorfinn Karlsefni.
|Thord of Hofdi|
(Þórðr fra Höfða Bjarnarson[† 1])
|Snorri Thordarson of Hofdi[† 2]||Vifil of Vifilsdale||Hallveig|
|Thord Snorrason Horse-head||Thorbjorn Vifilsson|
|Thorfinn Karlsefni||Gudrid Thorbjarnardóttir|
|Snorri Thorfinnsson||Thorbjorn Thorfinnsson|
|Hallfrid Snorradottir||Thorgeir Snorrason||(*) Steinunn[† 3]||Thorunn Thorbjarnardottir|
|Thorlak Runolfsson, Bp.[† 4]||Yngvild Thorgeirsdottir[† 5]||Bjorn Gilsson, Bp.[† 4]|
|Brand Sæmundarsson, Bp.[† 4]|
- Eiríks saga Ch. 7, Hauksbók version says "Thord, who lived at Hofdi, son of Bjorn Butter-Box" (Magnusson & Pálsson 1965, p. 91n)which is identifiable with "Thord Bjarnarson (at Hofdi)" in Kunz 2000, Index of Characters. However Thord Bjarnarson does not appear in Kunz's translation of Eiríks saga which does not use the Hauksbók version, and instead, appears only in Vatnsdál saga, another tale in the anthology,
- "of Hofdi" appended in Kunz 2000, Index of Characters, pp. 759–782, to distinguish from a man in Laxdæla saga
- This daughter Steinunn, as well as Haukr's mostly patrilineal line is only given in the Hauksbók manuscript, and his family tree will given under the article Haukr Erlendsson
- Bp.=short for "Bishop". For Bishop Björn and the first Bishop Brand, the patrynomycs are not given in text, but e.g. supplied in Kunz 2000, Index of Characters
- In Grl. she is spelt Yngveld, and this distinction is kept in Kunz's translations (Kunz 2000, pp. 651, 674); Text of Grl. :"Snorre atti son þann er Þorgæirr het hann var fadir Jnguelldar modur Branz byskups" (Storm 1891, p. 73)
- SNORRI KARLSEFINSSON used in Magnusson & Pálsson 1965, List of Proper Names", p.111
- Thrapp, Dan (1991), Encyclopedia of Frontier Biography: P-Z, University of Nebraska Press, ISBN 0-8032-9420-4
- Vésteinsson, Orri (2000), The Christianisation of Iceland: priests, power, and social change, 1000–1300, Oxford University Press, ISBN 0-19-820799-9
- Berry, Francis (1977), I tell of Greenland: an edited translation of the Sauđarkrokur manuscripts, University of Michigan, ISBN 0-7100-8591-5
- Mowat, Farley (1965), Westviking: the ancient Norse in Greenland and North America (snippet), University of Michigan, p. 224,
named Snorri, possibly in honor of Snorri Thorbrandsson, who seems not only to have been Karlsefni's closest comrade but to have also been the elder wise man of the expedition
- Glaumbær (Historical Places in Northwest Iceland)
- Mallet 1847, p. 261
- Magnússon, Magnús (1973), Viking expansion westwards, Bodley Head
- Magnusson & Pálsson 1965, Eir. ch.14, p.91 (1983 ed., p.71)
- Mallet, Paul Henri, Northern Antiquities, Harvard University Press
- Waters, Henry Fritz-Gilbert (1992), The New England Historical and Genealogical Register, Heritage Books, ISBN 1-55613-687-0
- Mallet 1847, p. 257n
- Blum, Ralph (2004), Rune Cards, Connections Book Publishing, ISBN 1-85906-138-9
- Explorers and Exploration, Marshall Cavendish Corporation, 2005, ISBN 0-7614-7535-4
- "Archaeology team unlocks the saga of Snorri Thorfinnsson", The Age, Melbourne, 17 September 2002
- "Glaumbaer – The first farmer". Skagafjordur Heritage Museum. Retrieved January 20, 2016.
- "The Snorri Program"
- The saga texts obviously do not bother to reiterate the patronymic form in nominative case at every instance. For the English forms of the patronymics, Kunz 2000, Index of Characters, pp. 759–782 is consulted.
- Kunz 2000, Spelling conventions, p. lxv–lxvi; Index of Characters pp. 759–782, "main rule.. to drop the nominative singular endings and use the stems instead. Thus Egil·l becomes Egil and.. (Auð·r becomes Aud)"
- patronymics after Kunz 2000, Index of Characters, pp. 759–782
- Magnusson & Pálsson 1965, Eir. ch.14, p.91, "H reads: Snorri Karlsefnisson had another daughter, called Steinunn, who married Einar, etc" extending to "Hauk the Lawman"; Storm 1891, p. 47, "Fra Dottir Snorra Karlsefnissvnar var ok Steinvnn er atti Einarr