2000
#3,630
National surname rank
Recorded bearers 8,986
First available Census row
Per 100,000 3.33
Uncommon Last name
Roby
A toponymic surname derived from a place name meaning "farmstead on a hill" in Old Danish.
According to the 2020 US Census Bureau surname tables, roughly 10,401 Americans carry the last name Roby. That puts it at #3,815 in the national surname ranking, appearing at a frequency of 3.03 per 100,000 people (about 1 in 32,954 residents).
This page is the full Name Census profile for the Roby 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.
For British records, Name Census UK has a British surname profile for Roby with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
10K
1 in 32,954
Census rank
#3,815
2020 decennial data
Per 100,000
3.0
Frequency rate
Recorded bearers
9.1K
uncommon in the US
Popularity narrative
The Census Bureau recorded 9,070 bearers of the surname Roby in its 2020 decennial surname file. At a rate of 3.03 per 100,000 residents, it holds the 3815th position in the national surname ranking.
Among Census respondents with the surname Roby, the largest self-reported group is White at 60.8%. The next largest groups are Black (29.9%) and Two or More Races (4.4%).
Origin
Meaning and origin of Roby
The surname Roby has its origins in England, emerging during the medieval period. It is believed to be derived from the Old French word "robe," which means "robe" or "garment." This suggests that the name may have initially referred to someone who made or sold robes or clothing.
One of the earliest recorded instances of the name Roby can be found in the Domesday Book, a comprehensive survey of land and property commissioned by William the Conqueror in 1086. The name appears in various spellings, such as "Robi" and "Robei," indicating its presence in England during the Norman era.
In the 13th century, records show the name Roby being associated with various locations in Lancashire, England. For example, the village of Roby Mill was mentioned in historical documents from this period, and it is possible that the surname originated from this place name or a similar one.
One notable individual bearing the surname Roby was John Roby, a 16th-century English clergyman and scholar. Born in 1495, he served as the Bishop of Norwich from 1537 until his death in 1558. He was known for his involvement in the English Reformation and his support for the Protestant cause.
In the 17th century, Thomas Roby, an English soldier and politician, gained prominence. Born in 1619, he served as a Member of Parliament for Shaftesbury and was actively involved in the English Civil War, fighting on the Parliamentarian side.
Another significant figure with the surname Roby was John Roby, an English Dissenting minister and author who lived from 1693 to 1768. He was known for his works on theology and his advocacy for religious freedom and nonconformity.
In the 18th century, the name Roby was also found in literary circles. William Roby, born in 1766, was an English writer and educator who authored several books on grammar and language instruction.
As the centuries progressed, the surname Roby continued to be present in various parts of England, with individuals bearing this name contributing to various fields, including religion, politics, and literature.
Demographics
Ancestry and ethnicity for Roby
Among Census respondents with the surname Roby, the largest self-reported group is White at 60.8%. The next largest groups are Black (29.9%) and Two or More Races (4.4%).
The bar chart below shows how Roby 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 Roby surname at the time of the 2020 Census, not any inherent property of the name itself.
- White60.8% · 5,511
- Black or African American29.9% · 2,709
- Two or more races4.4% · 398
- Hispanic or Latino2.9% · 263
- Asian and Pacific Islander1.8% · 163
- American Indian and Alaska Native0.3% · 26
Timeline
Historical Census data for Roby
Roby 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
#3,798
National surname rank
Recorded bearers 9,315
+329 bearers (+3.7%)
Per 100,000 3.16
Rank movement Down 168 places
2020
#3,815
National surname rank
Recorded bearers 9,070
-245 bearers (-2.6%)
Per 100,000 3.03
Rank movement Down 17 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #3,630 | 8,986 | 3.33 | First available Census row | First available Census row |
| 2010 | #3,798 | 9,315 | 3.16 | +329 bearers (+3.7%) | Down 168 places |
| 2020 | #3,815 | 9,070 | 3.03 | -245 bearers (-2.6%) | Down 17 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 Roby 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 | #3,798 | #3,815 | -0.4% |
| Count | 9,315 | 9,070 | -2.6% |
| Per 100K | 3.16 | 3.03 | -4.0% |
Between the 2010 and 2020 Census, the number of Roby bearers went from 9,315 to 9,070 (-2.6% change). The surname moved down 17 positions in the national ranking, going from #3,798 to #3,815.
FAQ
Roby surname: questions and answers
How many people in the U.S. have the surname Roby?
Name Census estimates that about 10,401 living Americans carry the surname Roby. Using the current population baseline, that works out to roughly 1 in 32,954 residents.
How common is Roby?
Roby ranks #3,815 in the 2020 Census surname tables and is classified on this site as "Uncommon." The Census recorded the name at a frequency of 3.03 per 100,000 residents, which is about 3 people out of every 100,000.
How many people with this surname were counted in the Census?
The raw 2020 Census file counted 9,070 people with the surname Roby. That is different from the site's living-bearer estimate (10,401), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 3.03 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 3.03 per 100,000 means that if you picked a random group of 100,000 U.S. residents, you would expect about 3 of them to have the surname Roby.
Has Roby become more or less common over time?
Between 2010 and 2020, the surname Roby went from 9,315 recorded bearers to 9,070. That is a decrease of 245 (-2.6%). In the national ranking it fell from #3,798 to #3,815.
What does the Census say about the background of Roby?
Among Census respondents with the surname Roby, the largest self-reported group is White at 60.8%. The next largest groups are Black (29.9%) and Two or More Races (4.4%). 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 Roby in the 2020 Census, accounting for 60.8% (5,511 people in the source table).
What is the full ancestry breakdown?
Roby appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (60.8%), Black (29.9%), Two or More Races (4.4%). 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 Roby (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 Roby mean?
A toponymic surname derived from a place name meaning "farmstead on a hill" in Old Danish. 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 Roby (3.03 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 people have the surname Roby?
For a quick modern estimate, our sister site HowManyOfMe.org answers that in one glance, with the living-bearer count front and centre.