2000
#9,989
National surname rank
Recorded bearers 2,978
First available Census row
Per 100,000 1.10
Rare Last name
Gilmartin
An Irish surname derived from the Gaelic "Mac Giolla Mhártain," meaning "son of the servant of Saint Martin."
According to the 2020 US Census Bureau surname tables, roughly 3,144 Americans carry the last name Gilmartin. That puts it at #11,064 in the national surname ranking, appearing at a frequency of 0.92 per 100,000 people (about 1 in 109,019 residents).
This page is the full Name Census profile for the Gilmartin 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 Gilmartin with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
3.1K
1 in 109,019
Census rank
#11,064
2020 decennial data
Per 100,000
0.9
Frequency rate
Recorded bearers
2.7K
rare in the US
Popularity narrative
The Census Bureau recorded 2,742 bearers of the surname Gilmartin in its 2020 decennial surname file. At a rate of 0.92 per 100,000 residents, it holds the 11064th position in the national surname ranking.
Among Census respondents with the surname Gilmartin, the largest self-reported group is White at 90.7%. The next largest groups are Hispanic (4.9%) and Two or More Races (2.7%).
Origin
Meaning and origin of Gilmartin
The surname Gilmartin originated in Ireland, deriving from the Gaelic personal name "Gilmartain" or "Gilmartan." This name is a combination of the elements "Gil," meaning "bright" or "servant," and "Martain," which is derived from the Latin name "Martinus," meaning "of Mars" or "warlike."
The earliest recorded instances of the name can be traced back to the 12th century in County Sligo, where it was associated with the Ui Briuin sept, a branch of the larger Connacht dynasty. The name was prominent in this region, particularly in the baronies of Carbury and Leyny.
In the 16th century, a notable bearer of the name was Fearghal Óg Gilmartin, who was a chieftain of the Ui Briuin sept in County Sligo. He played a significant role in the Nine Years' War (1593-1603) against English forces.
Another historical figure was Malachy Gilmartin (c. 1625-1679), an Irish Franciscan friar who served as the Bishop of Ardagh in County Longford from 1670 until his death. He was known for his efforts in promoting Catholic education and preserving religious heritage during a period of religious persecution.
In the 18th century, John Gilmartin (1725-1799) was a prominent Irish landowner and politician from County Mayo. He served as a Member of the Irish Parliament for the constituency of Sligo Borough from 1761 to 1768.
Moving to the 19th century, William Gilmartin (1808-1870) was an Irish-born architect who immigrated to the United States and designed several notable buildings in New York City, including the Old Metropolitan Opera House and the former New York World Building.
Another notable bearer of the name was Charles Gilmartin (1856-1924), an Irish-American politician who served as the 39th Mayor of Syracuse, New York, from 1908 to 1912.
The surname Gilmartin has also been recorded with various spelling variations over time, including Gilmarten, Gilmartyn, Kilmartin, and Kilmartyn, reflecting the regional dialects and phonetic adaptations across different parts of Ireland.
Demographics
Ancestry and ethnicity for Gilmartin
Among Census respondents with the surname Gilmartin, the largest self-reported group is White at 90.7%. The next largest groups are Hispanic (4.9%) and Two or More Races (2.7%).
The bar chart below shows how Gilmartin 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 Gilmartin surname at the time of the 2020 Census, not any inherent property of the name itself.
- White90.7% · 2,486
- Hispanic or Latino4.9% · 133
- Two or more races2.7% · 73
- American Indian and Alaska Native0.8% · 23
- Asian and Pacific Islander0.7% · 18
- Black or African American0.3% · 9
Timeline
Historical Census data for Gilmartin
Gilmartin 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
#11,062
National surname rank
Recorded bearers 2,872
-106 bearers (-3.6%)
Per 100,000 0.97
Rank movement Down 1,073 places
2020
#11,064
National surname rank
Recorded bearers 2,742
-130 bearers (-4.5%)
Per 100,000 0.92
Rank movement Down 2 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #9,989 | 2,978 | 1.10 | First available Census row | First available Census row |
| 2010 | #11,062 | 2,872 | 0.97 | -106 bearers (-3.6%) | Down 1,073 places |
| 2020 | #11,064 | 2,742 | 0.92 | -130 bearers (-4.5%) | Down 2 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 Gilmartin 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 | #11,062 | #11,064 | -0.0% |
| Count | 2,872 | 2,742 | -4.5% |
| Per 100K | 0.97 | 0.92 | -5.4% |
Between the 2010 and 2020 Census, the number of Gilmartin bearers went from 2,872 to 2,742 (-4.5% change). The surname moved down 2 positions in the national ranking, going from #11,062 to #11,064.
FAQ
Gilmartin surname: questions and answers
How many people in the U.S. have the surname Gilmartin?
Name Census estimates that about 3,144 living Americans carry the surname Gilmartin. Using the current population baseline, that works out to roughly 1 in 109,019 residents.
How common is Gilmartin?
Gilmartin ranks #11,064 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 0.92 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 2,742 people with the surname Gilmartin. That is different from the site's living-bearer estimate (3,144), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 0.92 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 0.92 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 Gilmartin.
Has Gilmartin become more or less common over time?
Between 2010 and 2020, the surname Gilmartin went from 2,872 recorded bearers to 2,742. That is a decrease of 130 (-4.5%). In the national ranking it fell from #11,062 to #11,064.
What does the Census say about the background of Gilmartin?
Among Census respondents with the surname Gilmartin, the largest self-reported group is White at 90.7%. The next largest groups are Hispanic (4.9%) 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 Gilmartin in the 2020 Census, accounting for 90.7% (2,486 people in the source table).
What is the full ancestry breakdown?
Gilmartin appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are White (90.7%), Hispanic (4.9%), 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 Gilmartin (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 Gilmartin mean?
An Irish surname derived from the Gaelic "Mac Giolla Mhártain," meaning "son of the servant of Saint Martin." 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 Gilmartin (0.92 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 Gilmartin?
Find out how many people are called Gilmartin on our sister site HowManyOfMe.org — a quick modern estimate with the living-bearer count front and centre.