2000
#9,531
National surname rank
Recorded bearers 3,128
First available Census row
Per 100,000 1.16
Rare Last name
Ohalloran
An Irish surname derived from the Gaelic "Ó hAllmhuráin," meaning "descendant of Allmhurán" (a personal name meaning "stranger" or "pirate").
According to the 2020 US Census Bureau surname tables, roughly 3,772 Americans carry the last name Ohalloran. That puts it at #9,462 in the national surname ranking, appearing at a frequency of 1.10 per 100,000 people (about 1 in 90,868 residents).
This page is the full Name Census profile for the Ohalloran 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 Ohalloran with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
3.8K
1 in 90,868
Census rank
#9,462
2020 decennial data
Per 100,000
1.1
Frequency rate
Recorded bearers
3.3K
rare in the US
Popularity narrative
The Census Bureau recorded 3,289 bearers of the surname Ohalloran in its 2020 decennial surname file. At a rate of 1.10 per 100,000 residents, it holds the 9462nd position in the national surname ranking.
Among Census respondents with the surname Ohalloran, the largest self-reported group is White at 91.3%. The next largest groups are Hispanic (4.7%) and Two or More Races (2.4%).
Origin
Meaning and origin of Ohalloran
The surname OHALLORAN is of Irish origin, tracing its roots back to the 16th century in the province of Munster. It is derived from the Gaelic Ó hAllmhuráin, which means "descendant of Allmhurán". Allmhurán was a personal name that likely originated from a combination of the Irish words "all" meaning "foreigner" and "muirn" meaning "affection" or "love".
One of the earliest recorded mentions of the name can be found in the Fiants of the Reign of Queen Elizabeth, where a James O'Halloran was listed as a landholder in County Cork in 1586. The name was also found in various Gaelic annals and chronicles from the same period, indicating its prevalence among the Gaelic Irish population.
During the 17th and 18th centuries, the OHALLORAN name was concentrated in counties Cork and Kerry, particularly in the baronies of Duhallow and Magunihy. Notable figures from this era include Reverend Donough O'Halloran (1615-1684), a Catholic priest and poet, and Sylvester O'Halloran (1728-1807), a prominent historian and author best known for his work "An Introduction to the Study of the Ancient History of Ireland".
In the 19th century, the name spread more widely across Ireland and beyond due to emigration. One notable bearer was Sir Joseph O'Halloran (1824-1899), an Irish lawyer and politician who served as Solicitor General for Ireland and a Member of Parliament for Cavan.
As the 20th century dawned, the name continued to be found throughout Ireland and in Irish communities abroad. Notable individuals include Michael O'Halloran (1888-1966), an Irish writer and politician, and Monsignor Patrick O'Halloran (1897-1978), a prominent Catholic clergyman who served as the President of St. Patrick's College in Thurles, County Tipperary.
While the OHALLORAN surname has its origins in a specific region of Ireland, it has since become widespread and can be found among Irish diaspora communities around the world, carrying with it the rich cultural heritage and history of the Gaelic Irish people.
Demographics
Ancestry and ethnicity for Ohalloran
Among Census respondents with the surname Ohalloran, the largest self-reported group is White at 91.3%. The next largest groups are Hispanic (4.7%) and Two or More Races (2.4%).
The bar chart below shows how Ohalloran 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 Ohalloran surname at the time of the 2020 Census, not any inherent property of the name itself.
- White91.3% · 3,004
- Hispanic or Latino4.7% · 154
- Two or more races2.4% · 79
- Asian and Pacific Islander1.0% · 34
- Black or African American0.4% · 12
- American Indian and Alaska Native0.2% · 6
Timeline
Historical Census data for Ohalloran
Ohalloran 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
#9,839
National surname rank
Recorded bearers 3,289
+161 bearers (+5.1%)
Per 100,000 1.11
Rank movement Down 308 places
2020
#9,462
National surname rank
Recorded bearers 3,289
+0 bearers (+0.0%)
Per 100,000 1.10
Rank movement Up 377 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #9,531 | 3,128 | 1.16 | First available Census row | First available Census row |
| 2010 | #9,839 | 3,289 | 1.11 | +161 bearers (+5.1%) | Down 308 places |
| 2020 | #9,462 | 3,289 | 1.10 | +0 bearers (+0.0%) | Up 377 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 Ohalloran 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 | #9,839 | #9,462 | 3.8% |
| Count | 3,289 | 3,289 | 0.0% |
| Per 100K | 1.11 | 1.10 | -0.9% |
Between the 2010 and 2020 Census, the number of Ohalloran bearers went from 3,289 to 3,289 (+0.0% change). The surname moved up 377 positions in the national ranking, going from #9,839 to #9,462.
Notable bearers
Famous people with the surname Ohalloran
FAQ
Ohalloran surname: questions and answers
How many people in the U.S. have the surname Ohalloran?
Name Census estimates that about 3,772 living Americans carry the surname Ohalloran. Using the current population baseline, that works out to roughly 1 in 90,868 residents.
How common is Ohalloran?
Ohalloran ranks #9,462 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 1.10 per 100,000 residents, which is about 1 people out of every 100,000.
How many people with this surname were counted in the Census?
The raw 2020 Census file counted 3,289 people with the surname Ohalloran. That is different from the site's living-bearer estimate (3,772), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 1.1 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 1.10 per 100,000 means that if you picked a random group of 100,000 U.S. residents, you would expect about 1 of them to have the surname Ohalloran.
Has Ohalloran become more or less common over time?
Between 2010 and 2020, the surname Ohalloran went from 3,289 recorded bearers to 3,289. That is an increase of 0 (+0.0%). In the national ranking it rose from #9,839 to #9,462.
What does the Census say about the background of Ohalloran?
Among Census respondents with the surname Ohalloran, the largest self-reported group is White at 91.3%. The next largest groups are Hispanic (4.7%) and Two or More Races (2.4%). 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 Ohalloran in the 2020 Census, accounting for 91.3% (3,004 people in the source table).
What is the full ancestry breakdown?
Ohalloran appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (91.3%), Hispanic (4.7%), Two or More Races (2.4%). 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 Ohalloran (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 Ohalloran mean?
An Irish surname derived from the Gaelic "Ó hAllmhuráin," meaning "descendant of Allmhurán" (a personal name meaning "stranger" or "pirate"). 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 Ohalloran (1.10 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 Ohalloran?
For a faster, more casual read, check HowManyOfMe.org — our sister site built around that single question.