2000
#9,491
National surname rank
Recorded bearers 3,141
First available Census row
Per 100,000 1.16
Rare Last name
Oloughlin
An Irish surname derived from the Gaelic "Ó Lochlainn," meaning "descendant of Lochlann" (a Viking).
According to the 2020 US Census Bureau surname tables, roughly 3,689 Americans carry the last name Oloughlin. That puts it at #9,651 in the national surname ranking, appearing at a frequency of 1.08 per 100,000 people (about 1 in 92,913 residents).
This page is the full Name Census profile for the Oloughlin 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 Oloughlin with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
3.7K
1 in 92,913
Census rank
#9,651
2020 decennial data
Per 100,000
1.1
Frequency rate
Recorded bearers
3.2K
rare in the US
Popularity narrative
The Census Bureau recorded 3,217 bearers of the surname Oloughlin in its 2020 decennial surname file. At a rate of 1.08 per 100,000 residents, it holds the 9651st position in the national surname ranking.
Among Census respondents with the surname Oloughlin, the largest self-reported group is White at 89.9%. The next largest groups are Hispanic (4.3%) and Two or More Races (2.7%).
Origin
Meaning and origin of Oloughlin
The surname OLOUGHLIN has its origins in Ireland and dates back to the late Middle Ages. It is an anglicized form of the Irish Gaelic name Ó Lochlainn, which means "descendant of Lochlainn". Lochlainn was a personal name derived from the old Norse word "lochlan", meaning "fjord dweller" or "from Norway".
This surname is found predominantly in the counties of Westmeath, Meath, and Offaly in the Irish Midlands. It is thought to be a branch of the Uí Néill royal dynasty that ruled parts of Ireland from the 5th to the 10th century. The earliest recorded example of the name is Amhalgaidh Ua Lochlainn, who was King of Cenél nEógain and High King of Ireland from 1014 to 1036.
In the Annals of Ulster, a medieval Irish chronicle, there are several references to individuals with the name Ua Lochlainn or Ó Lochlainn. For instance, Aodh Ó Lochlainn, who died in 1197, is mentioned as the King of Cenél nEógain and a prominent leader during the Norman invasion of Ireland.
Another notable figure was Muircheartach Ua Lochlainn, who was the High King of Ireland from 1156 to 1166. He is renowned for his military campaigns against the Anglo-Normans and for presiding over a period of relative peace and prosperity in Ireland.
In the 14th century, a branch of the Ó Lochlainn family settled in the Barony of Fartullagh, County Westmeath, where they became known as the OLOUGHLIN clan. One of the earliest recorded individuals with this anglicized spelling was John OLOUGHLIN, who was a member of the Irish Parliament in the late 16th century.
During the Williamite War in Ireland (1689-1691), several members of the OLOUGHLIN family fought on the Jacobite side, supporting the deposed Catholic King James II against the forces of King William III. Notable among them was Colonel Terence OLOUGHLIN, who commanded a regiment of dragoons and was killed in action at the Battle of Aughrim in 1691.
In the 18th century, a distinguished member of the family was Reverend Michael OLOUGHLIN, who was a prominent Catholic priest and writer. He was born in County Westmeath in 1737 and is best known for his work "A Brief View of the Tenets and Practices of the Ancient Irish", published in 1789.
Demographics
Ancestry and ethnicity for Oloughlin
Among Census respondents with the surname Oloughlin, the largest self-reported group is White at 89.9%. The next largest groups are Hispanic (4.3%) and Two or More Races (2.7%).
The bar chart below shows how Oloughlin 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 Oloughlin surname at the time of the 2020 Census, not any inherent property of the name itself.
- White89.9% · 2,891
- Hispanic or Latino4.3% · 138
- Two or more races2.7% · 87
- Black or African American2.1% · 68
- Asian and Pacific Islander0.8% · 27
- American Indian and Alaska Native0.2% · 6
Timeline
Historical Census data for Oloughlin
Oloughlin 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
#10,191
National surname rank
Recorded bearers 3,162
+21 bearers (+0.7%)
Per 100,000 1.07
Rank movement Down 700 places
2020
#9,651
National surname rank
Recorded bearers 3,217
+55 bearers (+1.7%)
Per 100,000 1.08
Rank movement Up 540 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #9,491 | 3,141 | 1.16 | First available Census row | First available Census row |
| 2010 | #10,191 | 3,162 | 1.07 | +21 bearers (+0.7%) | Down 700 places |
| 2020 | #9,651 | 3,217 | 1.08 | +55 bearers (+1.7%) | Up 540 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 Oloughlin 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 | #10,191 | #9,651 | 5.3% |
| Count | 3,162 | 3,217 | 1.7% |
| Per 100K | 1.07 | 1.08 | 0.6% |
Between the 2010 and 2020 Census, the number of Oloughlin bearers went from 3,162 to 3,217 (+1.7% change). The surname moved up 540 positions in the national ranking, going from #10,191 to #9,651.
FAQ
Oloughlin surname: questions and answers
How many people in the U.S. have the surname Oloughlin?
Name Census estimates that about 3,689 living Americans carry the surname Oloughlin. Using the current population baseline, that works out to roughly 1 in 92,913 residents.
How common is Oloughlin?
Oloughlin ranks #9,651 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 1.08 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 3,217 people with the surname Oloughlin. That is different from the site's living-bearer estimate (3,689), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 1.08 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 1.08 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 Oloughlin.
Has Oloughlin become more or less common over time?
Between 2010 and 2020, the surname Oloughlin went from 3,162 recorded bearers to 3,217. That is an increase of 55 (+1.7%). In the national ranking it rose from #10,191 to #9,651.
What does the Census say about the background of Oloughlin?
Among Census respondents with the surname Oloughlin, the largest self-reported group is White at 89.9%. The next largest groups are Hispanic (4.3%) and Two or More Races (2.7%). 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 Oloughlin in the 2020 Census, accounting for 89.9% (2,891 people in the source table).
What is the full ancestry breakdown?
Oloughlin appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (89.9%), Hispanic (4.3%), Two or More Races (2.7%). 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 Oloughlin (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 Oloughlin mean?
An Irish surname derived from the Gaelic "Ó Lochlainn," meaning "descendant of Lochlann" (a Viking). 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 Oloughlin (1.08 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 last name Oloughlin?
See how many people have the last name Oloughlin on HowManyOfMe.org, our sister site built around that single question.