2000
#12,986
National surname rank
Recorded bearers 2,164
First available Census row
Per 100,000 0.80
Rare Last name
Aldaco
A Basque surname derived from the place name Aldaco, meaning "place of alder trees."
According to the 2020 US Census Bureau surname tables, roughly 3,312 Americans carry the last name Aldaco. That puts it at #10,591 in the national surname ranking, appearing at a frequency of 0.97 per 100,000 people (about 1 in 103,489 residents).
This page is the full Name Census profile for the Aldaco 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
3.3K
1 in 103,489
Census rank
#10,591
2020 decennial data
Per 100,000
1.0
Frequency rate
Recorded bearers
2.9K
rare in the US
Popularity narrative
The Census Bureau recorded 2,888 bearers of the surname Aldaco in its 2020 decennial surname file. At a rate of 0.97 per 100,000 residents, it holds the 10591st position in the national surname ranking.
Among Census respondents with the surname Aldaco, the largest self-reported group is Hispanic at 93.6%. The next largest groups are White (5.0%) and Two or More Races (0.5%).
Origin
Meaning and origin of Aldaco
The surname Aldaco is believed to have originated in Spain during the medieval period. It is thought to be derived from the Basque words "alde," meaning "side" or "part," and "ko," a locative suffix indicating a place of origin. This suggests that the name may have initially referred to someone who lived near or came from a specific location.
One of the earliest recorded instances of the name Aldaco can be found in a 13th-century manuscript from the Basque region of Spain, where it appears as "Aldacoa." This variation in spelling was common in historical documents, as standardized spelling conventions were not widely adopted until much later.
In the 15th century, records show an individual named Juan Aldaco serving as a prominent military commander during the Reconquista, the campaign to reclaim the Iberian Peninsula from Moorish rule. His bravery and leadership earned him recognition, and his name appears in several chronicles of the time.
During the 16th century, the name Aldaco gained further prominence when a wealthy merchant family bearing the name established a successful trading business in the city of Seville. One member of this family, Diego Aldaco (c. 1520-1585), was known for his philanthropic efforts and support of local churches and charities.
In the 17th century, a renowned Spanish writer and poet, Miguel Aldaco (1612-1677), gained acclaim for his lyrical works celebrating the beauty of his native Basque region. His poems were widely circulated and helped to popularize the name Aldaco beyond its original geographical boundaries.
Another notable figure bearing the surname Aldaco was María Aldaco (1789-1862), a respected educator and advocate for women's education in Spain. She founded several schools and worked tirelessly to promote literacy and learning opportunities for girls and young women.
Throughout its history, the name Aldaco has maintained strong connections to its Spanish and Basque roots, with many bearers of the name tracing their ancestry back to these regions. While relatively uncommon outside of Spain, the surname remains a proud symbol of the country's rich cultural heritage and traditions.
Demographics
Ancestry and ethnicity for Aldaco
Among Census respondents with the surname Aldaco, the largest self-reported group is Hispanic at 93.6%. The next largest groups are White (5.0%) and Two or More Races (0.5%).
The bar chart below shows how Aldaco 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 Aldaco surname at the time of the 2020 Census, not any inherent property of the name itself.
- Hispanic or Latino93.6% · 2,704
- White5.0% · 144
- Two or more races0.5% · 15
- American Indian and Alaska Native0.3% · 9
- Black or African American0.3% · 8
- Asian and Pacific Islander0.3% · 8
Timeline
Historical Census data for Aldaco
Aldaco 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
#10,797
National surname rank
Recorded bearers 2,953
+789 bearers (+36.5%)
Per 100,000 1.00
Rank movement Up 2,189 places
2020
#10,591
National surname rank
Recorded bearers 2,888
-65 bearers (-2.2%)
Per 100,000 0.97
Rank movement Up 206 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #12,986 | 2,164 | 0.80 | First available Census row | First available Census row |
| 2010 | #10,797 | 2,953 | 1.00 | +789 bearers (+36.5%) | Up 2,189 places |
| 2020 | #10,591 | 2,888 | 0.97 | -65 bearers (-2.2%) | Up 206 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 Aldaco 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 | #10,797 | #10,591 | 1.9% |
| Count | 2,953 | 2,888 | -2.2% |
| Per 100K | 1.00 | 0.97 | -3.4% |
Between the 2010 and 2020 Census, the number of Aldaco bearers went from 2,953 to 2,888 (-2.2% change). The surname moved up 206 positions in the national ranking, going from #10,797 to #10,591.
FAQ
Aldaco surname: questions and answers
How many people in the U.S. have the surname Aldaco?
Name Census estimates that about 3,312 living Americans carry the surname Aldaco. Using the current population baseline, that works out to roughly 1 in 103,489 residents.
How common is Aldaco?
Aldaco ranks #10,591 in the 2020 Census surname tables and is classified on this site as "Rare." The Census recorded the name at a frequency of 0.97 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 2,888 people with the surname Aldaco. That is different from the site's living-bearer estimate (3,312), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 0.97 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 0.97 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 Aldaco.
Has Aldaco become more or less common over time?
Between 2010 and 2020, the surname Aldaco went from 2,953 recorded bearers to 2,888. That is a decrease of 65 (-2.2%). In the national ranking it rose from #10,797 to #10,591.
What does the Census say about the background of Aldaco?
Among Census respondents with the surname Aldaco, the largest self-reported group is Hispanic at 93.6%. The next largest groups are White (5.0%) and Two or More Races (0.5%). 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?
Hispanic is the largest self-reported group for the surname Aldaco in the 2020 Census, accounting for 93.6% (2,704 people in the source table).
What is the full ancestry breakdown?
Aldaco appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are Hispanic (93.6%), White (5.0%), Two or More Races (0.5%). 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 Aldaco (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 Aldaco mean?
A Basque surname derived from the place name Aldaco, meaning "place of alder trees." 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 Aldaco (0.97 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 Aldaco?
For a quick modern estimate, our sister site HowManyOfMe.org answers that in one glance, with the living-bearer count front and centre.