Thomassen
surname · Latin script
Meaning: a surname originating as a patronymic
Recorded for both men and women· direction only, no split published
Thomassen is a surname written in the Latin script, with more bearers in Norway than in any other country.
- NLNetherlands1 in 6.7K(measured from records)
- USUnited States1 in 708K
- GLGreenland1 in 311
carrying the name, as counted by each country's national register. One hue, darker where it is more common; hover a country for its figure.
- Norway (measured from records)
- Sources
- 153 (measured from records)
- 1 in 311 (inferred from the name graph)
11,070 people
Highest-authority source
Greenland
measured from records inferred from the name graph
Spellings & scripts(measured from records)
One other spelling is counted as the same name:
Spellings marked ● are how people bearing the name write it in our records, and ○ marks a model's transliteration; click a spelling to open its page.
Meaning & origin(measured from records)
a surname originating as a patronymic
Sources 1
- kaikki.org Wiktionary extract (IPA + transliterations)
Attested across 3 languages in the etymology graph.
Where in the world(measured from records)
Thomassen counted together with the spellings and other-language forms grouped with it. Where a register counted another spelling, the row names it.
Sorted by bearers: national registers' counts, and Mondonomo's estimates (≈, est.) where no register counts.
| Country | Most common spelling | Sources | |||
|---|---|---|---|---|---|
| NO Norway | 11,070 | 1 in 494 | 11K | Thomassen | 51 |
| NL Netherlands | 2,573 | 1 in 6.7K | 2.6K | Thomassen | 65 |
| DK Denmark | 2,294 | 1 in 2.6K | 2.3K | — | 3 |
| US United States | 470 | 1 in 708K | 587 | Thomassen | 153 |
| BE Belgium | 404 | 1 in 29K | 404 | Thomassen | 18 |
| GL Greenland | 185 | 1 in 311 | 185 | — | 1 |
11,070 people counted by SSB — Navnesøk (name-search service, living population). Exact figures are national registers' own counts, while figures marked ≈ and est. are Mondonomo’s estimates, counted from our sources and calibrated against those registers; hover one for how far to trust it in that country. A dash means neither exists.
Registers cited: SSB — Navnesøk (name-search service, living population); Census Bureau — Surname Frequency 2010; Census Bureau — Surname Frequency 2020; CBG Familienamenbank — Dutch surname bearer counts (GBA/BRP 2007); Danmarks Statistik — Hvor mange hedder...? (living-population name counts); Familienaam.be — Belgian family-name frequency (population register); Statistics Greenland — Surnames (NAXT1). Figures without a register are Mondonomo estimates; see Methodology.
Country figures for a list of names, at full precision, are available under licence rather than by scraping this table (how that works).
Other recorded senses(measured from records)
Thomassen is also recorded in 2 other lexicons, as a different name or as an ordinary word. These are senses of the spelling, not of the name above.
In German, Patronymisch zu Rufname Thomas; niederdeutsch/niederländisch -sen ‘Sohn des Thomas’; 267 Träger.
as a nameDeutscher Familiennamenatlas, Band 6: Familiennamen aus Rufnamen
In German, Patronymischer Familienname zu Rufname Thomas; niederrheinisch mit schwachem dt. Genitiv, teils -sen-Derivat.
as a nameDeutscher Familiennamenatlas, Band 6: Familiennamen aus Rufnamen
Ordered by how much of this spelling's record each language holds, so a sense from a language the name is barely used in sits last rather than first.
Notable people with this name(measured from records)
- Thomas Thomassenb. 1878NONorwegian actor (1878–1962)
- Reidar Thomassenb. 1936NOwriter (1936–2024)
- Magne Thomassenb. 1941NONorwegian speed skater
- Petter Thomassenb. 1941NONorwegian politician (1941-2003)
- Carsten Thomassenb. 1948DKDanish mathematician
- Mikkjal Thomassenb. 1976FOFaroese footballer and manager
- Dan Thomassenb. 1981DKDanish footballer
- Hedvig Mollestad Thomassenb. 1982NONorwegian guitarist
- Joachim Thomassenb. 1988NONorwegian footballer
- Frederikke Thomassenb. 1996Danish actress
The ten people covered by the most Wikipedia language editions — a proxy for cross-cultural notability, which favours historical and Western figures over equally prominent contemporary ones — shown by birth year. Source: Wikidata (CC0).
Evidence(measured from records)
Attested in 27 sources across 17 countries.
Reference works 3
- Nederlandse FamilienamenBank (Dutch surname bank; ex-Meertens Instituut, now CBG)2007
- Wikipedia surname tokens
- Wikidata name items (native-script + romanized given/family names)
These works list the name; their figures are licensed and are not reproduced here.
Register rows as of the 2026-10-09 data build.
Frequently asked questions
- What does the name Thomassen mean, and where does it come from?
- a surname originating as a patronymic Recorded by kaikki.org Wiktionary extract (IPA + transliterations).
- In which country does Thomassen have the most bearers?
- In Norway, the national register counted about 11 thousand people named Thomassen, more than in any other country we hold, where it is most often spelled thomassen.
- Where is Thomassen most common?
- Measured as a share of residents rather than as a count, Thomassen is densest in Greenland — about 1 in 311 people — even though Norway holds more of our records for it.
- How common is the name Thomassen?
- In Norway, the national register counted 11,070 people named Thomassen, about 1 in 494 residents.
What do you want to know about Thomassen?
Nobody replies to these one by one, but what readers ask decides what these pages answer next.
Query this name via API
curl -H "X-API-Key: YOUR_KEY" https://api.mondonomo.ai/api/v1/name-graph/thomassenThe payload this page is built from: spellings and scripts, countries and languages, related names, and the registers that attest the form. It takes a free API key (1,000 requests a day), which returns what this page shows everyone; the full country table, every register citation and the year-by-year series come with a licensed key, as does bulk access.
About this data
measured from records inferred from the name graph machine-generated
These figures come from the data snapshot of and will change as it is rebuilt.
Statistics are aggregated from the Mondonomo name corpus; related names and etymology are inferred from the name graph; pronunciation and any machine-marked transliterations are model-generated. Read how the numbers are made, including their known failure modes, and where the data comes from.
Reference works we consult — surname dictionaries, official name registers, Wikidata and Wiktionary — are named directly, beside the claims they support. The per-country source counts also include datasets of person records: we publish how many there are and their authority tier, but not their names.
Cite this page Mondonomo, “Thomassen”. Data snapshot 2026-10-10.