2000
#8,737
National surname rank
Recorded bearers 3,462
First available Census row
Per 100,000 1.28
Rare Last name
Galligan
An Irish surname derived from the Gaelic Ó Gallachóin, meaning "descendant of Gallchobhair," a personal name meaning "foreign helper."
According to the 2020 US Census Bureau surname tables, roughly 3,540 Americans carry the last name Galligan. That puts it at #9,974 in the national surname ranking, appearing at a frequency of 1.03 per 100,000 people (about 1 in 96,823 residents).
This page is the full Name Census profile for the Galligan 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 Galligan with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
3.5K
1 in 96,823
Census rank
#9,974
2020 decennial data
Per 100,000
1.0
Frequency rate
Recorded bearers
3.1K
rare in the US
Popularity narrative
The Census Bureau recorded 3,087 bearers of the surname Galligan in its 2020 decennial surname file. At a rate of 1.03 per 100,000 residents, it holds the 9974th position in the national surname ranking.
Among Census respondents with the surname Galligan, the largest self-reported group is White at 92.8%. The next largest groups are Hispanic (3.8%) and Two or More Races (2.0%).
Origin
Meaning and origin of Galligan
The surname Galligan has its origins in Ireland, where it first appeared in the late 16th or early 17th century. The name is believed to be a variant of the Irish Gaelic name Ó Gallchobhair, which means "descendant of Gallchobhair." Gallchobhair is a personal name derived from the Gaelic words "gall," meaning "foreigner" or "stranger," and "cobhair," meaning "help" or "aid."
One of the earliest recorded instances of the Galligan surname can be found in the Fiants of the Reign of Elizabeth I, a collection of Irish government records from the late 16th century. The name is also mentioned in various land and tax records from the 17th and 18th centuries in counties such as Mayo, Sligo, and Roscommon.
The Galligan surname has been associated with several notable individuals throughout history. One of the earliest recorded examples is Terence Galligan (c. 1640-1720), an Irish Catholic priest and historian who wrote extensively about the Irish Confederate Wars of the 1640s.
Another prominent figure was John Galligan (1829-1904), an Irish-born Australian politician who served as a member of the Victorian Legislative Council and was instrumental in the establishment of the Catholic Diocese of Ballarat.
In the United States, Michael J. Galligan (1847-1916) was a notable figure who served as a member of the Wisconsin State Assembly and as a judge in Milwaukee County. Additionally, Cornelius Galligan (1840-1908) was an Irish-American politician who served as a member of the New York State Assembly and as the first Roman Catholic Sheriff of New York County.
The Galligan surname has also been associated with several place names in Ireland, including Galligan's Cross in County Mayo and Galligan's Hill in County Roscommon. These place names likely originated from families or individuals bearing the Galligan surname who lived or owned land in those areas.
Throughout its history, the Galligan surname has undergone various spelling variations, such as Galigan, Gallegan, and Gallighan, reflecting regional dialects and the evolution of language over time.
Demographics
Ancestry and ethnicity for Galligan
Among Census respondents with the surname Galligan, the largest self-reported group is White at 92.8%. The next largest groups are Hispanic (3.8%) and Two or More Races (2.0%).
The bar chart below shows how Galligan 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 Galligan surname at the time of the 2020 Census, not any inherent property of the name itself.
- White92.8% · 2,866
- Hispanic or Latino3.8% · 116
- Two or more races2.0% · 63
- Asian and Pacific Islander0.7% · 23
- Black or African American0.6% · 19
Timeline
Historical Census data for Galligan
Galligan 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
#8,938
National surname rank
Recorded bearers 3,663
+201 bearers (+5.8%)
Per 100,000 1.24
Rank movement Down 201 places
2020
#9,974
National surname rank
Recorded bearers 3,087
-576 bearers (-15.7%)
Per 100,000 1.03
Rank movement Down 1,036 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #8,737 | 3,462 | 1.28 | First available Census row | First available Census row |
| 2010 | #8,938 | 3,663 | 1.24 | +201 bearers (+5.8%) | Down 201 places |
| 2020 | #9,974 | 3,087 | 1.03 | -576 bearers (-15.7%) | Down 1,036 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 Galligan 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 | #8,938 | #9,974 | -11.6% |
| Count | 3,663 | 3,087 | -15.7% |
| Per 100K | 1.24 | 1.03 | -16.7% |
Between the 2010 and 2020 Census, the number of Galligan bearers went from 3,663 to 3,087 (-15.7% change). The surname moved down 1,036 positions in the national ranking, going from #8,938 to #9,974.
FAQ
Galligan surname: questions and answers
How many people in the U.S. have the surname Galligan?
Name Census estimates that about 3,540 living Americans carry the surname Galligan. Using the current population baseline, that works out to roughly 1 in 96,823 residents.
How common is Galligan?
Galligan ranks #9,974 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 1.03 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 3,087 people with the surname Galligan. That is different from the site's living-bearer estimate (3,540), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 1.03 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 1.03 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 Galligan.
Has Galligan become more or less common over time?
Between 2010 and 2020, the surname Galligan went from 3,663 recorded bearers to 3,087. That is a decrease of 576 (-15.7%). In the national ranking it fell from #8,938 to #9,974.
What does the Census say about the background of Galligan?
Among Census respondents with the surname Galligan, the largest self-reported group is White at 92.8%. The next largest groups are Hispanic (3.8%) and Two or More Races (2.0%). 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 Galligan in the 2020 Census, accounting for 92.8% (2,866 people in the source table).
What is the full ancestry breakdown?
Galligan appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (92.8%), Hispanic (3.8%), Two or More Races (2.0%). 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 Galligan (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 Galligan mean?
An Irish surname derived from the Gaelic Ó Gallachóin, meaning "descendant of Gallchobhair," a personal name meaning "foreign helper." 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 Galligan (1.03 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 common is the surname Galligan?
Find out how many people are called Galligan on our sister site HowManyOfMe.org — a quick modern estimate with the living-bearer count front and centre.