Larsen

Larsen is a patronymic surname meaning “son of Lars.” It arose repeatedly in Denmark and Norway, and it is also documented in northern Germany. Originally, the name could describe a person's father rather than identify a permanent family: a man called Peder whose father was Lars might be recorded as Peder Larsen. Modern Larsen families therefore do not descend from one original bearer.

The Name Behind the Surname

The formation is Lars + the patronymic ending -sen, “son.” The Dictionary of American Family Names classifies Larsen as Danish, Norwegian, and North German and derives it from the personal name Lars. It also notes that some American occurrences of Larsen are Americanized from the cognate spelling Larssen.

Lars has a longer history than the surname. The University of Copenhagen's Dansk Navneleksikon describes it either as a short form of Latin Laurentius or, less certainly, as a Nordic contraction of Vulgar Latin Larentius. Laurentius meant “person from Laurentium,” referring to an ancient town southwest of Rome. Although the place-name contains Latin laurus, “laurel,” the familiar explanation “the laurel-crowned one” is a secondary reinterpretation, not the name's direct literal meaning.

This language history explains the name's form; it does not prove a Roman, Italian, or shared genealogical origin for people called Larsen.

When Larsen Was a Father-Name

Before hereditary surnames became general, Larsen could change from one generation to the next. If Peder Larsen had a son Niels, that child might be Niels Pedersen, not Niels Larsen. A daughter of Lars might instead appear as Larsdatter (“Lars's daughter”) in an older record. In that setting, the patronymic identified parentage at the time the record was made.

An inherited Larsen is different. Once a patronymic became a fixed family surname, children could remain Larsen even when their father was not named Lars. Scholars sometimes call this a secondary patronymic: a name that retains patronymic form but functions as a hereditary surname.

Denmark

The change did not occur everywhere at once. The University of Copenhagen's account of Danish surname history records an early intervention in Schleswig in 1771, when children were required to receive an unchanging family name. For the Kingdom of Denmark, an 1828 baptism ordinance required every child to be entered with a family or stem name as well as a given name. Guidance issued that year allowed a father's byname, a traditional patronymic, or a home-place name, but required all his children to share the selected surname. A further circular in 1829 directed that girls' patronymics use -sen rather than -datter.

Many rural families chose the ordinary patronymic as the new family name. A circular in 1856 then made the surname chosen under the earlier rules binding on later generations. That administrative history helps explain why numerous unrelated Danish families ended up with inherited -sen surnames such as Larsen.

Norway

Norwegian practice followed a different timetable. Olav Veka's account in Store norske leksikon estimates that only about two percent of Norway's population used fixed surnames around 1800; most people still used a patronymic, often with a farm name added as an address. Ivar Utne further notes that the same person could be recorded with a true patronymic, an inherited patronymic, or the name of the farm where he or she lived. Farm labels could change when a person moved, and spelling was not necessarily fixed.

Inherited surnames spread during the nineteenth century, especially in towns. Norway's first name law in 1923 required a fixed surname, although most residents had already adopted one by then. Consequently, a Larsen in a nineteenth-century Norwegian parish register may be a literal child of Lars, while a twentieth-century Larsen will ordinarily bear an inherited family name. The record's date and local naming practice determine which reading is appropriate.

Spellings and Related Names

These forms are related, but they should not be treated as interchangeable without evidence:

• Larssen is a cognate spelling with doubled s; the Oxford dictionary source notes that Larsen can be its Americanized form.
• Larson can be an Americanized form of Danish or Norwegian Larsen or Larssen, but it can also come from Swedish Larsson.
• Larsson is the regular Swedish patronymic from Lars. It shares the same underlying meaning but can have an independent Swedish origin.
• Larsdatter and Larsdotter are historical feminine patronymics, “daughter of Lars,” not spelling variants of Larsen.
• Laursen, Lauritsen, and Lauridsen are separate patronymics formed from related given names. Similarity does not show that a particular family changed from one to another.

Clerks, emigrants, and later indexers could alter a spelling, but a modern match between Larsen and Larson or Larsson is only a lead. Dates, places, relatives, and continuity across original records are needed to show that two forms refer to the same family.

Documented Distribution

Official statistics confirm that Larsen remains especially common in both Denmark and Norway. Statistics Denmark counted 112,454 residents whose registered last surname was Larsen on 1 January 2018; it was one of the country's ten most frequent -sen surnames. The agency's measure uses the final surname in the Central Person Register, so it does not combine Larsen with hyphenated or middle-name forms.

Statistics Norway's 2025 surname table counted 34,833 people named Larsen. It separately listed 1,534 named Larssen and 1,575 named Larsson, a useful reminder that official counts preserve spelling distinctions rather than merging every related form.

These totals show present-day frequency, not a single place of origin. Because Larsen was created independently from a very common given name and later fixed in many families, surname distribution cannot by itself establish a relationship between two Larsen lines.

What the Surname Can Establish

The etymology supports a narrow historical statement: at the point when a true patronymic Larsen was formed, it identified a son of a man called Lars. It does not identify which Lars, when the name first became hereditary in a particular family, or whether two bearers share ancestry.

For an individual record, the central question is therefore whether Larsen is being used as a live patronymic or a fixed surname. In Denmark, the 1828, 1829, and 1856 rules provide important chronological markers. In Norway, a patronymic and farm address may coexist well into the period before the 1923 law. Those national dates are guides rather than substitutes for the evidence in a particular parish or family.

References

• Patrick Hanks, Simon Lenarčič, and Peter McClure, eds., “Larsen,” *Dictionary of American Family Names*, 2nd ed. (Oxford University Press, 2022); see also the dictionary's entries for Larson and Larsson.
• Archive for Name Research, University of Copenhagen, “Lars,” *Dansk Navneleksikon*.
• University of Copenhagen, Archive for Name Research, “Efternavne i 1800-tallet”, on the 1771, 1828, 1829, and 1856 surname rules.
• Olav Veka, “etternamn,” *Store norske leksikon*, updated 24 June 2026.
• Gulbrand Alhaug, “patronymikon,” *Store norske leksikon*, updated 22 February 2025.
• Ivar Utne, “Etternavn og mellomnavn med familietradisjon,” *Nytt om namn*, no. 37 (2003), University of Bergen copy.
• Statistics Denmark, “Færrest med et SEN-efternavn i Ishøj Kommune”, Nyt fra Danmarks Statistik, no. 16 (16 January 2018).
• Statistics Norway, “Etternavn”, 2025 surname table.