2000
#112,365
National surname rank
Recorded bearers 145
First available Census row
Per 100,000 0.05
Very Rare Last name
Mullay
A surname derived from a place name in Ireland.
According to the 2020 US Census Bureau surname tables, roughly 116 Americans carry the last name Mullay. That puts it at #155,270 in the national surname ranking, appearing at a frequency of 0.03 per 100,000 people (about 1 in 2,954,779 residents).
This page is the full Name Census profile for the Mullay 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 Mullay with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
116
1 in 2,954,779
Census rank
#155,270
2020 decennial data
Per 100,000
0.0
Frequency rate
Recorded bearers
101
very rare in the US
Popularity narrative
The Census Bureau recorded 101 bearers of the surname Mullay in its 2020 decennial surname file. At a rate of 0.03 per 100,000 residents, it holds the 155270th position in the national surname ranking.
Among Census respondents with the surname Mullay, the largest self-reported group is White at 90.1%. The next largest groups are Hispanic (5.0%) and Asian/Pacific Islander (3.0%).
Origin
Meaning and origin of Mullay
The surname MULLAY is believed to have originated in Ireland, with its roots dating back to the 12th century. It is derived from the Irish Gaelic word "mullach," which means "summit" or "top of a hill." This suggests that the name may have been initially given to someone who lived on or near a hilltop.
One of the earliest recorded instances of the MULLAY surname is found in the Annals of the Four Masters, a historical chronicle compiled in the 17th century. It mentions a family called "Ó Mullaigh" residing in County Mayo during the 13th century. Over time, the spelling evolved to its current form, MULLAY.
In the 16th century, the MULLAY name appeared in the Fiants of the Tudor Sovereigns, a collection of official records from the Tudor period. One notable individual was Thomas MULLAY, who was granted lands in County Mayo in 1548.
During the 17th century, the MULLAY family played a significant role in the Irish Confederate Wars. Patrick MULLAY (1620-1690), a member of the Irish Catholic Confederation, served as a prominent military commander and later fled to France after the Cromwellian conquest.
Another notable figure was Edmond MULLAY (1675-1742), a Jacobite army officer who fought in the Battle of the Boyne and later served in the Irish Brigade of the French army. His memoirs provide valuable insights into the life of an Irish soldier during that period.
In the 18th century, the MULLAY name was associated with the town of Ballina, County Mayo, where a prominent family resided. One member, John MULLAY (1742-1819), was a successful merchant and landowner known for his philanthropic efforts.
In the 19th century, the MULLAY name gained further recognition with the birth of William MULLAY (1835-1901), a renowned Irish historian and author who wrote extensively on the history of County Mayo and the Irish diaspora.
Throughout history, the MULLAY surname has maintained a strong presence in Ireland, particularly in the western counties of Mayo and Sligo. While the name has seen various spellings, such as Mullally, Mullaly, and Mulley, the core meaning and origins remain rooted in the Irish Gaelic language and the country's rich heritage.
Demographics
Ancestry and ethnicity for Mullay
Among Census respondents with the surname Mullay, the largest self-reported group is White at 90.1%. The next largest groups are Hispanic (5.0%) and Asian/Pacific Islander (3.0%).
The bar chart below shows how Mullay 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 Mullay surname at the time of the 2020 Census, not any inherent property of the name itself.
- White90.1% · 91
- Hispanic or Latino5.0% · 5
- Asian and Pacific Islander3.0% · 3
- Two or more races2.0% · 2
Timeline
Historical Census data for Mullay
Mullay 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
#142,108
National surname rank
Recorded bearers 117
-28 bearers (-19.3%)
Per 100,000 0.04
Rank movement Down 29,743 places
2020
#155,270
National surname rank
Recorded bearers 101
-16 bearers (-13.7%)
Per 100,000 0.03
Rank movement Down 13,162 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #112,365 | 145 | 0.05 | First available Census row | First available Census row |
| 2010 | #142,108 | 117 | 0.04 | -28 bearers (-19.3%) | Down 29,743 places |
| 2020 | #155,270 | 101 | 0.03 | -16 bearers (-13.7%) | Down 13,162 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 Mullay 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 | #142,108 | #155,270 | -9.3% |
| Count | 117 | 101 | -13.7% |
| Per 100K | 0.04 | 0.03 | -15.5% |
Between the 2010 and 2020 Census, the number of Mullay bearers went from 117 to 101 (-13.7% change). The surname moved down 13,162 positions in the national ranking, going from #142,108 to #155,270.
FAQ
Mullay surname: questions and answers
How many people in the U.S. have the surname Mullay?
Name Census estimates that about 116 living Americans carry the surname Mullay. Using the current population baseline, that works out to roughly 1 in 2,954,779 residents.
How common is Mullay?
Mullay ranks #155,270 in the 2020 Census surname tables and is classified on this site as "Very Rare." The Census recorded the name at a frequency of 0.03 per 100,000 residents, which is about 0 people out of every 100,000.
How many people with this surname were counted in the Census?
The raw 2020 Census file counted 101 people with the surname Mullay. That is different from the site's living-bearer estimate (116), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 0.03 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 0.03 per 100,000 means that if you picked a random group of 100,000 U.S. residents, you would expect about 0 of them to have the surname Mullay.
Has Mullay become more or less common over time?
Between 2010 and 2020, the surname Mullay went from 117 recorded bearers to 101. That is a decrease of 16 (-13.7%). In the national ranking it fell from #142,108 to #155,270.
What does the Census say about the background of Mullay?
Among Census respondents with the surname Mullay, the largest self-reported group is White at 90.1%. The next largest groups are Hispanic (5.0%) and Asian/Pacific Islander (3.0%). 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 Mullay in the 2020 Census, accounting for 90.1% (91 people in the source table).
What is the full ancestry breakdown?
Mullay appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (90.1%), Hispanic (5.0%), Asian/Pacific Islander (3.0%). 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 Mullay (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 Mullay mean?
A surname derived from a place name in Ireland. 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 Mullay (0.03 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 many people have the surname Mullay?
HowManyOfMe.org, our sister site, answers that with the living-bearer count in one glance.