2000
#4,315
National surname rank
Recorded bearers 7,613
First available Census row
Per 100,000 2.82
Rare Last name
Monaghan
A surname of Irish origin, derived from the Gaelic "Ó Manacháin," meaning "descendant of the monk."
According to the 2020 US Census Bureau surname tables, roughly 8,833 Americans carry the last name Monaghan. That puts it at #4,466 in the national surname ranking, appearing at a frequency of 2.58 per 100,000 people (about 1 in 38,804 residents).
This page is the full Name Census profile for the Monaghan 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 Monaghan with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
8.8K
1 in 38,804
Census rank
#4,466
2020 decennial data
Per 100,000
2.6
Frequency rate
Recorded bearers
7.7K
rare in the US
Popularity narrative
The Census Bureau recorded 7,703 bearers of the surname Monaghan in its 2020 decennial surname file. At a rate of 2.58 per 100,000 residents, it holds the 4466th position in the national surname ranking.
Among Census respondents with the surname Monaghan, the largest self-reported group is White at 93.1%. The next largest groups are Two or More Races (2.7%) and Hispanic (2.6%).
Origin
Meaning and origin of Monaghan
The surname Monaghan originates from Ireland and can be traced back to the early medieval period. It is a locational name derived from the Irish Gaelic 'Muineachán,' meaning 'little plain' or 'little thicket.' This name refers to the town of Monaghan in County Monaghan, which was established by Irish monks in the 5th century.
The earliest recorded instance of the name can be found in the Annals of Ulster, which mentions a chieftain named Muiredach Muineachán who died in 767 AD. In the 12th century, the Book of Leinster, an important medieval Irish manuscript, also includes references to individuals with the surname Muineachán or Monaghan.
During the Anglo-Norman invasion of Ireland in the late 12th century, the spelling of the name evolved to its modern form, Monaghan. One notable bearer of this surname was Hugh Monaghan, a prominent Irish chieftain who fought against the English forces in the late 16th century.
In the 17th century, the name appears in various historical records, including the 1659 Census of Ireland, which lists several Monaghan families living in County Monaghan and neighboring counties. One prominent figure from this period was Patrick Monaghan (1630-1706), a Catholic prelate who served as the Bishop of Raphoe.
In the 18th century, the Monaghan family continued to play an important role in Irish history. Notably, Andrew Monaghan (1743-1820) was a member of the Irish Patriot movement and fought alongside the United Irishmen during the Irish Rebellion of 1798.
Other notable individuals with the surname Monaghan include:
1. James Monaghan (1831-1910), an Irish-American Catholic priest and educator who co-founded the University of Detroit Mercy.
2. John Monaghan (1878-1916), an Irish nationalist and member of the Irish Republican Brotherhood who participated in the Easter Rising of 1916.
3. Dorothy Monaghan (1895-1971), an American actress and vaudeville performer known for her roles in several silent films.
4. Tom Monaghan (born 1937), an American entrepreneur and founder of the Domino's Pizza chain.
5. Brendan Monaghan (born 1958), an Irish Gaelic football player and manager who played for the Dublin senior football team.
Demographics
Ancestry and ethnicity for Monaghan
Among Census respondents with the surname Monaghan, the largest self-reported group is White at 93.1%. The next largest groups are Two or More Races (2.7%) and Hispanic (2.6%).
The bar chart below shows how Monaghan 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 Monaghan surname at the time of the 2020 Census, not any inherent property of the name itself.
- White93.1% · 7,168
- Two or more races2.7% · 209
- Hispanic or Latino2.6% · 201
- Asian and Pacific Islander0.6% · 50
- American Indian and Alaska Native0.5% · 38
- Black or African American0.5% · 37
Timeline
Historical Census data for Monaghan
Monaghan 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
#4,452
National surname rank
Recorded bearers 7,968
+355 bearers (+4.7%)
Per 100,000 2.70
Rank movement Down 137 places
2020
#4,466
National surname rank
Recorded bearers 7,703
-265 bearers (-3.3%)
Per 100,000 2.58
Rank movement Down 14 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #4,315 | 7,613 | 2.82 | First available Census row | First available Census row |
| 2010 | #4,452 | 7,968 | 2.70 | +355 bearers (+4.7%) | Down 137 places |
| 2020 | #4,466 | 7,703 | 2.58 | -265 bearers (-3.3%) | Down 14 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 Monaghan 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 | #4,452 | #4,466 | -0.3% |
| Count | 7,968 | 7,703 | -3.3% |
| Per 100K | 2.70 | 2.58 | -4.6% |
Between the 2010 and 2020 Census, the number of Monaghan bearers went from 7,968 to 7,703 (-3.3% change). The surname moved down 14 positions in the national ranking, going from #4,452 to #4,466.
Notable bearers
Famous people with the surname Monaghan
FAQ
Monaghan surname: questions and answers
How many people in the U.S. have the surname Monaghan?
Name Census estimates that about 8,833 living Americans carry the surname Monaghan. Using the current population baseline, that works out to roughly 1 in 38,804 residents.
How common is Monaghan?
Monaghan ranks #4,466 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 2.58 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 7,703 people with the surname Monaghan. That is different from the site's living-bearer estimate (8,833), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 2.58 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 2.58 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 Monaghan.
Has Monaghan become more or less common over time?
Between 2010 and 2020, the surname Monaghan went from 7,968 recorded bearers to 7,703. That is a decrease of 265 (-3.3%). In the national ranking it fell from #4,452 to #4,466.
What does the Census say about the background of Monaghan?
Among Census respondents with the surname Monaghan, the largest self-reported group is White at 93.1%. The next largest groups are Two or More Races (2.7%) and Hispanic (2.6%). 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 Monaghan in the 2020 Census, accounting for 93.1% (7,168 people in the source table).
What is the full ancestry breakdown?
Monaghan appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (93.1%), Two or More Races (2.7%), Hispanic (2.6%). 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 Monaghan (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 Monaghan mean?
A surname of Irish origin, derived from the Gaelic "Ó Manacháin," meaning "descendant of the monk." 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 Monaghan (2.58 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 are called Monaghan?
If you just want to know how many Americans have the surname Monaghan, HowManyOfMe.org gives you the headline number in one glance.