2000
#150,436
National surname rank
Recorded bearers 100
First available Census row
Per 100,000 0.04
Very Rare Last name
Os
Possibly derived from a placename referring to a forest clearing.
According to the 2020 US Census Bureau surname tables, roughly 116 Americans carry the last name Os. That puts it at #155,270 in the national surname ranking, appearing at a frequency of 0.03 per 100,000 people (about 1 in 2,954,779 residents).
This page is the full Name Census profile for the Os 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
116
1 in 2,954,779
Census rank
#155,270
2020 decennial data
Per 100,000
0.0
Frequency rate
Recorded bearers
101
very rare in the US
Popularity narrative
The Census Bureau recorded 101 bearers of the surname Os in its 2020 decennial surname file. At a rate of 0.03 per 100,000 residents, it holds the 155270th position in the national surname ranking.
Among Census respondents with the surname Os, the largest self-reported group is White at 66.3%. The next largest groups are Hispanic (19.8%) and Black (6.9%).
Origin
Meaning and origin of Os
The surname "Os" is believed to have originated in Norway during the medieval period, around the 11th or 12th century. It is derived from the Old Norse word "oss," which means "mouth of a river" or "estuary." This suggests that the name may have initially been associated with people who lived near the mouth of a river or in a coastal region.
One of the earliest recorded instances of the name "Os" can be found in the Diplomatarium Norvegicum, a collection of medieval Norwegian documents dating back to the 12th century. In this collection, there are references to individuals with the surname "Os" living in various parts of Norway.
During the Viking Age, which lasted from the late 8th century to the late 11th century, the name "Os" may have been used by Norwegians who ventured to other parts of Europe and established settlements. For example, there are records of individuals with the surname "Os" living in parts of England and Scotland during the medieval period.
In the 13th century, a man named Ivar Os was mentioned in the Icelandic sagas as a prominent chieftain and landowner in Iceland. He is believed to have been born in Norway before relocating to Iceland, where he played a significant role in local politics and conflicts.
Another notable historical figure with the surname "Os" was Nils Pedersen Os, a Norwegian priest and historian who lived in the 16th century. He is best known for his work "Norges Beskrivelse" (Description of Norway), which provided valuable insights into the geography, culture, and history of Norway during that time.
In the 17th century, a Norwegian explorer named Jens Eriksen Os gained fame for his expeditions to Svalbard and other Arctic regions. He is credited with discovering and naming several islands and landmarks in the Arctic archipelago.
As the name "Os" spread throughout Norway and beyond, it also underwent various spelling variations, such as "Oss," "Osse," and "Osse." Additionally, some individuals with this surname may have adopted place names as part of their full surname, such as "Os fra Trondheim" (Os from Trondheim) or "Os fra Bergen" (Os from Bergen), indicating their place of origin.
While the surname "Os" is relatively uncommon outside of Norway and its neighboring regions, it has a rich historical significance and connections to the country's coastal and maritime traditions.
Demographics
Ancestry and ethnicity for Os
Among Census respondents with the surname Os, the largest self-reported group is White at 66.3%. The next largest groups are Hispanic (19.8%) and Black (6.9%).
The bar chart below shows how Os 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 Os surname at the time of the 2020 Census, not any inherent property of the name itself.
- White66.3% · 67
- Hispanic or Latino19.8% · 20
- Black or African American6.9% · 7
- Asian and Pacific Islander5.9% · 6
- American Indian and Alaska Native1.0% · 1
Timeline
Historical Census data for Os
Os 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
#156,044
National surname rank
Recorded bearers 104
+4 bearers (+4.0%)
Per 100,000 0.04
Rank movement Down 5,608 places
2020
#155,270
National surname rank
Recorded bearers 101
-3 bearers (-2.9%)
Per 100,000 0.03
Rank movement Up 774 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #150,436 | 100 | 0.04 | First available Census row | First available Census row |
| 2010 | #156,044 | 104 | 0.04 | +4 bearers (+4.0%) | Down 5,608 places |
| 2020 | #155,270 | 101 | 0.03 | -3 bearers (-2.9%) | Up 774 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 Os 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 | #156,044 | #155,270 | 0.5% |
| Count | 104 | 101 | -2.9% |
| Per 100K | 0.04 | 0.03 | -15.5% |
Between the 2010 and 2020 Census, the number of Os bearers went from 104 to 101 (-2.9% change). The surname moved up 774 positions in the national ranking, going from #156,044 to #155,270.
FAQ
Os surname: questions and answers
How many people in the U.S. have the surname Os?
Name Census estimates that about 116 living Americans carry the surname Os. Using the current population baseline, that works out to roughly 1 in 2,954,779 residents.
How common is Os?
Os ranks #155,270 in the 2020 Census surname tables and is classified on this site as "Very Rare." The Census recorded the name at a frequency of 0.03 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 101 people with the surname Os. That is different from the site's living-bearer estimate (116), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 0.03 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 0.03 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 Os.
Has Os become more or less common over time?
Between 2010 and 2020, the surname Os went from 104 recorded bearers to 101. That is a decrease of 3 (-2.9%). In the national ranking it rose from #156,044 to #155,270.
What does the Census say about the background of Os?
Among Census respondents with the surname Os, the largest self-reported group is White at 66.3%. The next largest groups are Hispanic (19.8%) and Black (6.9%). 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 Os in the 2020 Census, accounting for 66.3% (67 people in the source table).
What is the full ancestry breakdown?
Os appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (66.3%), Hispanic (19.8%), Black (6.9%). 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 Os (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 Os mean?
Possibly derived from a placename referring to a forest clearing. 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 Os (0.03 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 Americans have the surname Os?
For a quick modern estimate, our sister site HowManyOfMe.org answers that in one glance, with the living-bearer count front and centre.