2000
#3,961
National surname rank
Recorded bearers 8,228
First available Census row
Per 100,000 3.05
Rare Last name
Shanahan
Derived from the Irish surname Ó Seanachain, meaning "descendant of Seanachán," an ancient Irish personal name meaning "old" or "wise."
According to the 2020 US Census Bureau surname tables, roughly 9,681 Americans carry the last name Shanahan. That puts it at #4,078 in the national surname ranking, appearing at a frequency of 2.82 per 100,000 people (about 1 in 35,405 residents).
This page is the full Name Census profile for the Shanahan 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 Shanahan with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
9.7K
1 in 35,405
Census rank
#4,078
2020 decennial data
Per 100,000
2.8
Frequency rate
Recorded bearers
8.4K
rare in the US
Popularity narrative
The Census Bureau recorded 8,442 bearers of the surname Shanahan in its 2020 decennial surname file. At a rate of 2.82 per 100,000 residents, it holds the 4078th position in the national surname ranking.
Among Census respondents with the surname Shanahan, the largest self-reported group is White at 92.2%. The next largest groups are Hispanic (3.7%) and Two or More Races (2.5%).
Origin
Meaning and origin of Shanahan
The surname Shanahan originates from Ireland and is derived from the Irish Gaelic name O'Sionnachain, which means "descendant of Sionnach." Sionnach translates to "fox" in English, suggesting that the name may have been a nickname for someone with reddish hair or a sly, cunning personality.
The name first appeared in historical records in the 12th century, with the earliest known mention being in the Annals of the Four Masters, a chronicle of medieval Irish history. This reference dates back to 1176 and mentions a man named Sionnachain O'Sionnachain.
The Shanahan surname is most closely associated with County Limerick and County Tipperary in Ireland, where it has been concentrated for centuries. However, the name can also be found in other parts of Ireland, particularly in counties Cork and Kerry.
One notable early bearer of the name was Mathew Shanahan, a 16th-century Irish chieftain and leader of the Shanahan clan in County Limerick. He fought against the English during the Desmond Rebellions in the 1580s.
Another prominent figure was Edmund Shanahan (1757-1825), an Irish-born architect and builder who was active in Charleston, South Carolina, in the late 18th and early 19th centuries. He designed several notable buildings in the city, including the Charleston Orphan House and the Charleston Theater.
In the 19th century, Michael Shanahan (1825-1901) was a prominent Irish-American politician and lawyer who served as a member of the New York State Assembly and as a judge in New York City.
John Shanahan (1846-1917) was an Irish-American businessman and politician who served as the mayor of New Haven, Connecticut, from 1901 to 1905.
In more recent times, Dennis Shanahan (born 1949) is an Australian journalist and political commentator who has worked for various publications, including The Australian newspaper.
While the exact origins of the Shanahan surname may be lost to history, its Irish roots and connections to County Limerick and County Tipperary are well-established. The name has been carried by many notable individuals throughout the centuries, reflecting its enduring legacy.
Demographics
Ancestry and ethnicity for Shanahan
Among Census respondents with the surname Shanahan, the largest self-reported group is White at 92.2%. The next largest groups are Hispanic (3.7%) and Two or More Races (2.5%).
The bar chart below shows how Shanahan 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 Shanahan surname at the time of the 2020 Census, not any inherent property of the name itself.
- White92.2% · 7,783
- Hispanic or Latino3.7% · 313
- Two or more races2.5% · 213
- Asian and Pacific Islander0.9% · 78
- Black or African American0.5% · 42
- American Indian and Alaska Native0.2% · 13
Timeline
Historical Census data for Shanahan
Shanahan 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
#4,119
National surname rank
Recorded bearers 8,616
+388 bearers (+4.7%)
Per 100,000 2.92
Rank movement Down 158 places
2020
#4,078
National surname rank
Recorded bearers 8,442
-174 bearers (-2.0%)
Per 100,000 2.82
Rank movement Up 41 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #3,961 | 8,228 | 3.05 | First available Census row | First available Census row |
| 2010 | #4,119 | 8,616 | 2.92 | +388 bearers (+4.7%) | Down 158 places |
| 2020 | #4,078 | 8,442 | 2.82 | -174 bearers (-2.0%) | Up 41 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 Shanahan 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 | #4,119 | #4,078 | 1.0% |
| Count | 8,616 | 8,442 | -2.0% |
| Per 100K | 2.92 | 2.82 | -3.3% |
Between the 2010 and 2020 Census, the number of Shanahan bearers went from 8,616 to 8,442 (-2.0% change). The surname moved up 41 positions in the national ranking, going from #4,119 to #4,078.
Notable bearers
Famous people with the surname Shanahan
FAQ
Shanahan surname: questions and answers
How many people in the U.S. have the surname Shanahan?
Name Census estimates that about 9,681 living Americans carry the surname Shanahan. Using the current population baseline, that works out to roughly 1 in 35,405 residents.
How common is Shanahan?
Shanahan ranks #4,078 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 2.82 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 8,442 people with the surname Shanahan. That is different from the site's living-bearer estimate (9,681), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 2.82 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 2.82 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 Shanahan.
Has Shanahan become more or less common over time?
Between 2010 and 2020, the surname Shanahan went from 8,616 recorded bearers to 8,442. That is a decrease of 174 (-2.0%). In the national ranking it rose from #4,119 to #4,078.
What does the Census say about the background of Shanahan?
Among Census respondents with the surname Shanahan, the largest self-reported group is White at 92.2%. The next largest groups are Hispanic (3.7%) and Two or More Races (2.5%). 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 Shanahan in the 2020 Census, accounting for 92.2% (7,783 people in the source table).
What is the full ancestry breakdown?
Shanahan appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (92.2%), Hispanic (3.7%), Two or More Races (2.5%). 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 Shanahan (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 Shanahan mean?
Derived from the Irish surname Ó Seanachain, meaning "descendant of Seanachán," an ancient Irish personal name meaning "old" or "wise." 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 Shanahan (2.82 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 Shanahan?
For a quick modern estimate, our sister site HowManyOfMe.org answers that in one glance, with the living-bearer count front and centre.