2000
#142,819
National surname rank
Recorded bearers 107
First available Census row
Per 100,000 0.04
Very Rare Last name
Thorfinnson
An Old Norse patronymic surname indicating the son of someone named Thorfinn.
According to the 2020 US Census Bureau surname tables, roughly 122 Americans carry the last name Thorfinnson. That puts it at #152,339 in the national surname ranking, appearing at a frequency of 0.04 per 100,000 people (about 1 in 2,809,462 residents).
This page is the full Name Census profile for the Thorfinnson surname. You will find the Census Bureau frequency data, a multi-census history view, an ancestry and ethnicity breakdown based on self-reported demographics, the name's meaning and origin where available, and answers to the most common questions people ask about this surname.
Bearers in the US
122
1 in 2,809,462
Census rank
#152,339
2020 decennial data
Per 100,000
0.0
Frequency rate
Recorded bearers
106
very rare in the US
Popularity narrative
The Census Bureau recorded 106 bearers of the surname Thorfinnson in its 2020 decennial surname file. At a rate of 0.04 per 100,000 residents, it holds the 152339th position in the national surname ranking.
Among Census respondents with the surname Thorfinnson, the largest self-reported group is White at 97.2%. The next largest groups are Black (1.9%) and Hispanic (0.9%).
Origin
Meaning and origin of Thorfinnson
The surname Thorfinnson has its origins in the Nordic countries, particularly Iceland and Norway, dating back to the Viking era around the 9th to 11th centuries. It is a patronymic name, meaning "son of Thorfinn," where Thorfinn is a compound Norse name derived from the elements "Thor," the name of the Norse god of thunder, and "finn," meaning "Finn" or "person from Finland."
One of the earliest recorded instances of the name Thorfinnson can be found in the Icelandic Sagas, which document the lives and adventures of Norse settlers in Iceland. The Orkneyinga Saga, written in the early 13th century, mentions a powerful Norse earl named Thorfinn Thorfinnson, who ruled over the Orkney Islands and parts of mainland Scotland in the 11th century.
Another notable historical figure bearing the name Thorfinnson was Thorvald Thorfinnson, an Icelandic explorer who is believed to have been the first European to set foot in what is now North America. According to the Greenland Saga, Thorvald was part of an expedition led by his brother Leif Erikson around the year 1000 AD, and they established a short-lived settlement in present-day Newfoundland.
In the late 13th century, a Norwegian nobleman named Audun Thorfinnson was appointed as the first lawspeaker (lögmaður) of Iceland, responsible for reciting and interpreting the Icelandic law code known as the Grágás.
During the Middle Ages, the name Thorfinnson was also found in various records and documents in the Scandinavian countries. For example, a charter from the Danish town of Roskilde, dated 1378, mentions a man named Thorfinn Thorfinnson, who was a landowner in the area.
In more recent times, one notable bearer of the surname Thorfinnson was Guðmundur Thorfinnson (1874-1958), an Icelandic politician and diplomat who served as the first Minister of Iceland to the United States from 1941 to 1944.
While the surname Thorfinnson is relatively uncommon today, it remains a testament to the rich cultural heritage and historical significance of the Norse people, particularly in the regions where they settled and left their mark.
Demographics
Ancestry and ethnicity for Thorfinnson
Among Census respondents with the surname Thorfinnson, the largest self-reported group is White at 97.2%. The next largest groups are Black (1.9%) and Hispanic (0.9%).
The bar chart below shows how Thorfinnson bearers described their own race and ethnicity on the 2020 Census form. The Census Bureau groups responses into six broad categories: White, Black or African American, Hispanic or Latino, Asian and Pacific Islander, American Indian and Alaska Native, and Two or More Races. When a category has too few respondents for a given surname, the Bureau suppresses the figure to protect individual privacy, which is why some names show fewer than six slices.
Percentages are shown for every Census year so the breakdown stays comparable over time. When the source file also includes raw headcounts, Name Census shows those alongside the percentages in the legend.
Keep in mind that these are self-reported numbers. A person's surname does not determine their race or ethnicity, and the distribution you see here reflects the specific population who happened to carry the Thorfinnson surname at the time of the 2020 Census, not any inherent property of the name itself.
- White97.2% · 103
- Black or African American1.9% · 2
- Hispanic or Latino0.9% · 1
Timeline
Historical Census data for Thorfinnson
Thorfinnson appears in 3 published Census surname files: 2000, 2010, 2020. The cards below show how the name's rank and bearer count changed across each release.
2010
#160,975
National surname rank
Recorded bearers 100
-7 bearers (-6.5%)
Per 100,000 0.03
Rank movement Down 18,156 places
2020
#152,339
National surname rank
Recorded bearers 106
+6 bearers (+6.0%)
Per 100,000 0.04
Rank movement Up 8,636 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #142,819 | 107 | 0.04 | First available Census row | First available Census row |
| 2010 | #160,975 | 100 | 0.03 | -7 bearers (-6.5%) | Down 18,156 places |
| 2020 | #152,339 | 106 | 0.04 | +6 bearers (+6.0%) | Up 8,636 places |
For 2020, the Census Bureau published race and Hispanic-origin columns as counts rather than percentages. Name Census converts those counts back into shares so the ancestry section stays comparable with the older surname files.
Year on year
2010 vs 2020 Census
How has the Thorfinnson surname changed between Census years? The chart shows bearer count side by side, and the table compares rank, count, and frequency.
Census year comparison
20102020
| Metric | 2010 | 2020 | Change |
|---|---|---|---|
| Rank | #160,975 | #152,339 | 5.4% |
| Count | 100 | 106 | 6.0% |
| Per 100K | 0.03 | 0.04 | 18.2% |
Between the 2010 and 2020 Census, the number of Thorfinnson bearers went from 100 to 106 (+6.0% change). The surname moved up 8,636 positions in the national ranking, going from #160,975 to #152,339.
FAQ
Thorfinnson surname: questions and answers
How many people in the U.S. have the surname Thorfinnson?
Name Census estimates that about 122 living Americans carry the surname Thorfinnson. Using the current population baseline, that works out to roughly 1 in 2,809,462 residents.
How common is Thorfinnson?
Thorfinnson ranks #152,339 in the 2020 Census surname tables and is classified on this site as "Very Rare." The Census recorded the name at a frequency of 0.04 per 100,000 residents, which is about 0 people out of every 100,000.
How many people with this surname were counted in the Census?
The raw 2020 Census file counted 106 people with the surname Thorfinnson. That is different from the site's living-bearer estimate (122), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 0.04 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 0.04 per 100,000 means that if you picked a random group of 100,000 U.S. residents, you would expect about 0 of them to have the surname Thorfinnson.
Has Thorfinnson become more or less common over time?
Between 2010 and 2020, the surname Thorfinnson went from 100 recorded bearers to 106. That is an increase of 6 (+6.0%). In the national ranking it rose from #160,975 to #152,339.
What does the Census say about the background of Thorfinnson?
Among Census respondents with the surname Thorfinnson, the largest self-reported group is White at 97.2%. The next largest groups are Black (1.9%) and Hispanic (0.9%). These figures come from the 2020 Census Bureau surname tables, based on how respondents described their own race and ethnicity.
Which group reports this surname most often?
White is the largest self-reported group for the surname Thorfinnson in the 2020 Census, accounting for 97.2% (103 people in the source table).
What is the full ancestry breakdown?
Thorfinnson appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (97.2%), Black (1.9%), Hispanic (0.9%). For 2020, the source file also published raw headcounts for each group, which is why this page can show both percentages and counts in the ancestry section.
Is this page using the latest Census data?
Yes. This page is using the latest surname file currently loaded on Name Census, which is 2020. The historical section above also keeps any older Census surname entries we have for Thorfinnson (2000, 2010, 2020).
Does the Census include every surname?
No. The Census Bureau only publishes surnames that appeared at least 100 times in a given decennial Census. That means very rare surnames are excluded entirely, and a surname can appear in one Census release but disappear from a later one if it falls below the reporting threshold.
Why don't the ancestry percentages always add up to exactly 100%?
There are two main reasons: rounding and suppression. The Census Bureau rounds published values, and it may suppress very small cells to protect privacy. For 2020, the Bureau also published raw group counts rather than direct percentages, so Name Census converts those counts back into shares for comparability across census years.
What does Thorfinnson mean?
An Old Norse patronymic surname indicating the son of someone named Thorfinn. The fuller origin note on this page goes into more detail.
Where does the surname data come from?
All surname statistics on Name Census are drawn from the US Census Bureau's decennial surname frequency tables. These files list every surname that appeared 100 or more times in the 2020 Census, along with a count, a per-100,000 rate, and a self-reported demographic breakdown. You can read the full explanation on our methodology page.
How does Name Census estimate living bearers?
For surnames, Name Census does not age cohorts the way it does for first names. Instead, it takes the Census Bureau's published frequency for Thorfinnson (0.04 per 100,000) and applies that rate to the current U.S. resident population to estimate how many living Americans have the surname today.
How many people share the surname Thorfinnson?
For a faster, more casual read, check HowManyOfMe.org — our sister site built around that single question.