2000
#135,837
National surname rank
Recorded bearers 114
First available Census row
Per 100,000 0.04
Very Rare Last name
Sidlowski
A Polish surname derived from a town or village name.
According to the 2020 US Census Bureau surname tables, roughly 123 Americans carry the last name Sidlowski. That puts it at #151,639 in the national surname ranking, appearing at a frequency of 0.04 per 100,000 people (about 1 in 2,786,621 residents).
This page is the full Name Census profile for the Sidlowski 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
123
1 in 2,786,621
Census rank
#151,639
2020 decennial data
Per 100,000
0.0
Frequency rate
Recorded bearers
107
very rare in the US
Popularity narrative
The Census Bureau recorded 107 bearers of the surname Sidlowski in its 2020 decennial surname file. At a rate of 0.04 per 100,000 residents, it holds the 151639th position in the national surname ranking.
Among Census respondents with the surname Sidlowski, the largest self-reported group is White at 97.2%. The next largest groups are Two or More Races (1.9%) and American Indian/Alaska Native (0.9%).
Origin
Meaning and origin of Sidlowski
The surname Sidlowski originated in Poland, with records dating back to the 16th century. It is believed to be derived from the Polish word "siedlisko," which means "homestead" or "settlement." This suggests that the name may have been originally given to someone who lived on a homestead or in a particular settlement.
One of the earliest recorded instances of the Sidlowski name can be found in the historic records of the Krakow region, where a person named Jan Sidlowski was mentioned in a document dated 1578. Another early reference is in the church records of the town of Bialystok, where a Marianna Sidlowska was recorded in 1624.
The name Sidlowski has undergone some spelling variations over the centuries, with similar forms such as Sidlowski, Sidlowsky, and Sedlowski appearing in various records. These variations likely reflect regional dialects or scribal errors in the original recordings.
While no famous historical figures with the Sidlowski surname immediately come to mind, the name was certainly present throughout Polish history. Some notable individuals bearing this name include:
1. Józef Sidlowski (1832-1896), a Polish painter and art teacher active in the late 19th century.
2. Kazimierz Sidlowski (1887-1944), a Polish military officer who fought in World War I and later served in the Polish resistance during World War II.
3. Maria Sidlowska (1898-1976), a Polish writer and poet who published several collections of poetry and prose works in the early 20th century.
4. Tadeusz Sidlowski (1924-2001), a Polish engineer and inventor who held numerous patents for his innovations in the field of mechanical engineering.
5. Anna Sidlowska (born 1962), a contemporary Polish artist known for her abstract paintings and sculptures.
While the Sidlowski name may not be among the most prominent in Polish history, its origins and presence throughout the centuries reflect the rich cultural heritage of Poland and the stories of the many families who bore this surname over time.
Demographics
Ancestry and ethnicity for Sidlowski
Among Census respondents with the surname Sidlowski, the largest self-reported group is White at 97.2%. The next largest groups are Two or More Races (1.9%) and American Indian/Alaska Native (0.9%).
The bar chart below shows how Sidlowski 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 Sidlowski surname at the time of the 2020 Census, not any inherent property of the name itself.
- White97.2% · 104
- Two or more races1.9% · 2
- American Indian and Alaska Native0.9% · 1
Timeline
Historical Census data for Sidlowski
Sidlowski 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
#148,347
National surname rank
Recorded bearers 111
-3 bearers (-2.6%)
Per 100,000 0.04
Rank movement Down 12,510 places
2020
#151,639
National surname rank
Recorded bearers 107
-4 bearers (-3.6%)
Per 100,000 0.04
Rank movement Down 3,292 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #135,837 | 114 | 0.04 | First available Census row | First available Census row |
| 2010 | #148,347 | 111 | 0.04 | -3 bearers (-2.6%) | Down 12,510 places |
| 2020 | #151,639 | 107 | 0.04 | -4 bearers (-3.6%) | Down 3,292 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 Sidlowski 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 | #148,347 | #151,639 | -2.2% |
| Count | 111 | 107 | -3.6% |
| Per 100K | 0.04 | 0.04 | -10.5% |
Between the 2010 and 2020 Census, the number of Sidlowski bearers went from 111 to 107 (-3.6% change). The surname moved down 3,292 positions in the national ranking, going from #148,347 to #151,639.
FAQ
Sidlowski surname: questions and answers
How many people in the U.S. have the surname Sidlowski?
Name Census estimates that about 123 living Americans carry the surname Sidlowski. Using the current population baseline, that works out to roughly 1 in 2,786,621 residents.
How common is Sidlowski?
Sidlowski ranks #151,639 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 107 people with the surname Sidlowski. That is different from the site's living-bearer estimate (123), 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 Sidlowski.
Has Sidlowski become more or less common over time?
Between 2010 and 2020, the surname Sidlowski went from 111 recorded bearers to 107. That is a decrease of 4 (-3.6%). In the national ranking it fell from #148,347 to #151,639.
What does the Census say about the background of Sidlowski?
Among Census respondents with the surname Sidlowski, the largest self-reported group is White at 97.2%. The next largest groups are Two or More Races (1.9%) and American Indian/Alaska Native (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 Sidlowski in the 2020 Census, accounting for 97.2% (104 people in the source table).
What is the full ancestry breakdown?
Sidlowski appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (97.2%), Two or More Races (1.9%), American Indian/Alaska Native (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 Sidlowski (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 Sidlowski mean?
A Polish surname derived from a town or village name. 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 Sidlowski (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 are called Sidlowski?
Our sister site HowManyOfMe.org answers how many Americans have the surname Sidlowski at a glance, with the living-bearer count up front.