2000
#102,691
National surname rank
Recorded bearers 162
First available Census row
Per 100,000 0.06
Very Rare Last name
Idalgo
A variant spelling of the Spanish surname "Hidalgo", meaning a nobleman or gentleman.
According to the 2020 US Census Bureau surname tables, roughly 135 Americans carry the last name Idalgo. That puts it at #143,511 in the national surname ranking, appearing at a frequency of 0.04 per 100,000 people (about 1 in 2,538,921 residents).
This page is the full Name Census profile for the Idalgo 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.
Bearers in the US
135
1 in 2,538,921
Census rank
#143,511
2020 decennial data
Per 100,000
0.0
Frequency rate
Recorded bearers
118
very rare in the US
Popularity narrative
The Census Bureau recorded 118 bearers of the surname Idalgo in its 2020 decennial surname file. At a rate of 0.04 per 100,000 residents, it holds the 143511th position in the national surname ranking.
Among Census respondents with the surname Idalgo, the largest self-reported group is Hispanic at 97.5%. The next largest groups are White (0.8%) and Asian/Pacific Islander (0.8%).
Origin
Meaning and origin of Idalgo
The surname IDALGO has its origins in Spain, dating back to the medieval period. It is believed to be a variant of the Spanish word "hidalgo," which referred to a member of the lower nobility or gentry in Spain. The prefix "hi-" or "hijo" in Spanish means "son," while "dalgo" derives from the Latin phrase "de algo," meaning "of something" or "of worth."
The name IDALGO was likely first used to distinguish individuals who were the sons of hidalgos or members of the gentry class. These families often held land and enjoyed certain privileges, such as exemption from taxes and the right to carry weapons. The name may have originated in the regions of Castile or Andalusia, where the hidalgo class was particularly prominent.
One of the earliest recorded instances of the surname IDALGO appears in the "Libro de la Montería," a 14th-century hunting treatise commissioned by King Alfonso XI of Castile. The text mentions a "Juan Idalgo" who participated in hunting expeditions with the king.
In the 15th century, a notable figure named Diego Idalgo was a Spanish explorer and navigator who accompanied Christopher Columbus on his second voyage to the Americas in 1493. Idalgo played a role in the exploration and settlement of the Caribbean islands.
During the 16th century, the IDALGO surname was found in various regions of Spain, including the provinces of Seville, Cordoba, and Granada. One notable bearer was Antonio Idalgo de Quintana (c. 1530-1605), a Spanish philosopher and writer who authored works on ethics and moral philosophy.
In the 17th century, Juan Idalgo y Mendoza (1622-1692) was a Spanish military officer and governor of several provinces in South America. He served as the governor of Tucumán (modern-day Argentina) and played a significant role in the expansion and defense of Spanish territories in the region.
Another historical figure with the IDALGO surname was María Idalgo (1768-1803), a Spanish revolutionary and writer who advocated for women's rights and education. She was active during the Enlightenment period and published several works promoting feminist ideas.
While the IDALGO surname has its roots in Spain, it has spread to other parts of the world through migration and settlement. However, detailed historical records and references outside of Spain become more limited, as the name's origins are firmly rooted in the Spanish culture and tradition.
Demographics
Ancestry and ethnicity for Idalgo
Among Census respondents with the surname Idalgo, the largest self-reported group is Hispanic at 97.5%. The next largest groups are White (0.8%) and Asian/Pacific Islander (0.8%).
The bar chart below shows how Idalgo 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 Idalgo surname at the time of the 2020 Census, not any inherent property of the name itself.
- Hispanic or Latino97.5% · 115
- White0.8% · 1
- Asian and Pacific Islander0.8% · 1
- American Indian and Alaska Native0.8% · 1
Timeline
Historical Census data for Idalgo
Idalgo 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
#113,155
National surname rank
Recorded bearers 155
-7 bearers (-4.3%)
Per 100,000 0.05
Rank movement Down 10,464 places
2020
#143,511
National surname rank
Recorded bearers 118
-37 bearers (-23.9%)
Per 100,000 0.04
Rank movement Down 30,356 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #102,691 | 162 | 0.06 | First available Census row | First available Census row |
| 2010 | #113,155 | 155 | 0.05 | -7 bearers (-4.3%) | Down 10,464 places |
| 2020 | #143,511 | 118 | 0.04 | -37 bearers (-23.9%) | Down 30,356 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 Idalgo 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 | #113,155 | #143,511 | -26.8% |
| Count | 155 | 118 | -23.9% |
| Per 100K | 0.05 | 0.04 | -21.0% |
Between the 2010 and 2020 Census, the number of Idalgo bearers went from 155 to 118 (-23.9% change). The surname moved down 30,356 positions in the national ranking, going from #113,155 to #143,511.
FAQ
Idalgo surname: questions and answers
How many people in the U.S. have the surname Idalgo?
Name Census estimates that about 135 living Americans carry the surname Idalgo. Using the current population baseline, that works out to roughly 1 in 2,538,921 residents.
How common is Idalgo?
Idalgo ranks #143,511 in the 2020 Census surname tables and is classified on this site as "Very Rare." The Census recorded the name at a frequency of 0.04 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 118 people with the surname Idalgo. That is different from the site's living-bearer estimate (135), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 0.04 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 0.04 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 Idalgo.
Has Idalgo become more or less common over time?
Between 2010 and 2020, the surname Idalgo went from 155 recorded bearers to 118. That is a decrease of 37 (-23.9%). In the national ranking it fell from #113,155 to #143,511.
What does the Census say about the background of Idalgo?
Among Census respondents with the surname Idalgo, the largest self-reported group is Hispanic at 97.5%. The next largest groups are White (0.8%) and Asian/Pacific Islander (0.8%). 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?
Hispanic is the largest self-reported group for the surname Idalgo in the 2020 Census, accounting for 97.5% (115 people in the source table).
What is the full ancestry breakdown?
Idalgo appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are Hispanic (97.5%), White (0.8%), Asian/Pacific Islander (0.8%). 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 Idalgo (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 Idalgo mean?
A variant spelling of the Spanish surname "Hidalgo", meaning a nobleman or gentleman. 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 Idalgo (0.04 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 Americans have the surname Idalgo?
For a quick modern estimate, our sister site HowManyOfMe.org answers that in one glance, with the living-bearer count front and centre.