2000
#385
National surname rank
Recorded bearers 74,756
First available Census row
Per 100,000 27.71
Uncommon Last name
Oconnor
A surname of Irish origin, meaning a descendant of Conchobhar, derived from the Old Irish name meaning "wolf-lover" or "hound-lover."
According to the 2020 US Census Bureau surname tables, roughly 87,514 Americans carry the last name Oconnor. That puts it at #416 in the national surname ranking, appearing at a frequency of 25.53 per 100,000 people (about 1 in 3,917 residents).
This page is the full Name Census profile for the Oconnor 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 Oconnor with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
88K
1 in 3,917
Census rank
#416
2020 decennial data
Per 100,000
25.5
Frequency rate
Recorded bearers
76K
uncommon in the US
Popularity narrative
The Census Bureau recorded 76,316 bearers of the surname Oconnor in its 2020 decennial surname file. At a rate of 25.53 per 100,000 residents, it holds the 416th position in the national surname ranking.
Among Census respondents with the surname Oconnor, the largest self-reported group is White at 90.0%. The next largest groups are Hispanic (3.8%) and Two or More Races (2.7%).
Origin
Meaning and origin of Oconnor
The surname OCONNOR is an ancient Irish surname with roots dating back to the 5th century AD. It originated in Ireland, specifically in the province of Connacht, where it was an anglicized version of the Gaelic name Ó Conchobhair, meaning "descendant of Conchobhar."
The name Conchobhar itself is derived from the Old Irish words "con" meaning hound and "chabhar" meaning desire or valour. It was a popular personal name among the Irish nobility, particularly in the powerful Uí Briúin dynasty that ruled Connacht for centuries.
One of the earliest recorded instances of the name OCONNOR can be found in the Annals of the Four Masters, a chronicle of medieval Irish history compiled in the early 17th century. It mentions several prominent figures bearing the name, including Toirdelbach Ua Conchobair, who was King of Connacht from 1106 to 1156.
During the Norman invasion of Ireland in the 12th century, the OCONNOR family played a significant role in resisting the Norman advance. They were among the last Gaelic royal families to maintain power in Ireland, with their kingdom centered around the ancient capital of Cruachan in modern-day County Roscommon.
One of the most famous historical figures with the surname OCONNOR was Rory O'Connor (1116-1198), the last High King of Ireland. He led the Irish resistance against the Anglo-Norman invaders and was eventually forced to abdicate in 1186, marking the end of the traditional Irish monarchy.
Other notable individuals with the surname OCONNOR include:
1. Arthur O'Connor (1763-1852), a Irish revolutionary and leader of the United Irishmen.
2. Frank O'Connor (1903-1966), an Irish author and memoirist, best known for his short story collection "Guests of the Nation."
3. Sandra Day O'Connor (born 1930), the first woman appointed to the United States Supreme Court, serving from 1981 to 2006.
4. Sinéad O'Connor (born 1966), an Irish singer-songwriter known for her distinctive voice and controversial public persona.
5. Donald O'Connor (1925-2003), an American singer, dancer, and actor who starred in numerous musicals and comedies, including "Singin' in the Rain."
Throughout its long history, the surname OCONNOR has maintained a strong connection to its Irish roots, even as its bearers have spread across the world. It remains a proud symbol of the ancient Gaelic heritage and the enduring spirit of the Irish people.
Demographics
Ancestry and ethnicity for Oconnor
Among Census respondents with the surname Oconnor, the largest self-reported group is White at 90.0%. The next largest groups are Hispanic (3.8%) and Two or More Races (2.7%).
The bar chart below shows how Oconnor 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 Oconnor surname at the time of the 2020 Census, not any inherent property of the name itself.
- White90.0% · 68,695
- Hispanic or Latino3.8% · 2,894
- Two or more races2.7% · 2,089
- Black or African American2.2% · 1,708
- Asian and Pacific Islander1.0% · 736
- American Indian and Alaska Native0.3% · 194
Timeline
Historical Census data for Oconnor
Oconnor 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
#417
National surname rank
Recorded bearers 77,923
+3,167 bearers (+4.2%)
Per 100,000 26.42
Rank movement Down 32 places
2020
#416
National surname rank
Recorded bearers 76,316
-1,607 bearers (-2.1%)
Per 100,000 25.53
Rank movement Up 1 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #385 | 74,756 | 27.71 | First available Census row | First available Census row |
| 2010 | #417 | 77,923 | 26.42 | +3,167 bearers (+4.2%) | Down 32 places |
| 2020 | #416 | 76,316 | 25.53 | -1,607 bearers (-2.1%) | Up 1 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 Oconnor 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 | #417 | #416 | 0.2% |
| Count | 77,923 | 76,316 | -2.1% |
| Per 100K | 26.42 | 25.53 | -3.4% |
Between the 2010 and 2020 Census, the number of Oconnor bearers went from 77,923 to 76,316 (-2.1% change). The surname moved up 1 positions in the national ranking, going from #417 to #416.
Notable bearers
Famous people with the surname Oconnor
FAQ
Oconnor surname: questions and answers
How many people in the U.S. have the surname Oconnor?
Name Census estimates that about 87,514 living Americans carry the surname Oconnor. Using the current population baseline, that works out to roughly 1 in 3,917 residents.
How common is Oconnor?
Oconnor ranks #416 in the 2020 Census surname tables and is classified on this site as "Uncommon." The Census recorded the name at a frequency of 25.53 per 100,000 residents, which is about 26 people out of every 100,000.
How many people with this surname were counted in the Census?
The raw 2020 Census file counted 76,316 people with the surname Oconnor. That is different from the site's living-bearer estimate (87,514), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 25.53 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 25.53 per 100,000 means that if you picked a random group of 100,000 U.S. residents, you would expect about 26 of them to have the surname Oconnor.
Has Oconnor become more or less common over time?
Between 2010 and 2020, the surname Oconnor went from 77,923 recorded bearers to 76,316. That is a decrease of 1,607 (-2.1%). In the national ranking it rose from #417 to #416.
What does the Census say about the background of Oconnor?
Among Census respondents with the surname Oconnor, the largest self-reported group is White at 90.0%. The next largest groups are Hispanic (3.8%) 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 Oconnor in the 2020 Census, accounting for 90.0% (68,695 people in the source table).
What is the full ancestry breakdown?
Oconnor appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (90.0%), Hispanic (3.8%), 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 Oconnor (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 Oconnor mean?
A surname of Irish origin, meaning a descendant of Conchobhar, derived from the Old Irish name meaning "wolf-lover" or "hound-lover." 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 Oconnor (25.53 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 Oconnor?
For a faster, more casual read, check HowManyOfMe.org — our sister site built around that single question.