2000
#135
National surname rank
Recorded bearers 165,473
First available Census row
Per 100,000 61.34
Common Last name
Castillo
A Spanish topographical surname referring to someone who lived near a castle or fortified building.
According to the 2020 US Census Bureau surname tables, roughly 265,292 Americans carry the last name Castillo. That puts it at #94 in the national surname ranking, appearing at a frequency of 77.40 per 100,000 people (about 1 in 1,292 residents).
This page is the full Name Census profile for the Castillo 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 Castillo with 1881 census detail, origin facts and modern UK distribution where available.
Bearers in the US
265K
1 in 1,292
Census rank
#94
2020 decennial data
Per 100,000
77.4
Frequency rate
Recorded bearers
231K
common in the US
Popularity narrative
The Census Bureau recorded 231,347 bearers of the surname Castillo in its 2020 decennial surname file. At a rate of 77.40 per 100,000 residents, it holds the 94th position in the national surname ranking.
Among Census respondents with the surname Castillo, the largest self-reported group is Hispanic at 89.4%. The next largest groups are White (5.2%) and Asian/Pacific Islander (3.4%).
Origin
Meaning and origin of Castillo
The surname Castillo has its origins in Spain and is derived from the Spanish word "castillo," which means "castle." This name was likely first adopted by individuals who lived near or were associated with a particular castle or fortified structure during the medieval period in Spain.
One of the earliest recorded instances of the surname Castillo can be found in the Domesday Book, a comprehensive record of landowners in England compiled by order of William the Conqueror in 1086. The entry mentions a landowner named Radulfus de Castello, whose surname translates to "of the castle" in English.
During the 12th and 13th centuries, the surname Castillo began to spread throughout the Iberian Peninsula as the Spanish kingdoms expanded their territories and established new settlements. Some of the earliest recorded bearers of this name include Garci Fernandez de Castillo, a nobleman from the Kingdom of Castile who lived in the late 12th century, and Rodrigo Alvarez de Castillo, a knight who participated in the Reconquista against the Moors in the 13th century.
As the Spanish colonial empire expanded in the 15th and 16th centuries, the surname Castillo was carried to the Americas by explorers, settlers, and conquistadors. One notable figure was Bernal Diaz del Castillo (1492-1584), a Spanish soldier and historian who accompanied Hernán Cortés on his expedition to Mexico and wrote a firsthand account of the conquest.
Another prominent individual with the surname Castillo was Diego de Castillo Hernández (1551-1618), a Spanish mathematician and astronomer who made significant contributions to the development of navigation techniques and the calculation of longitudes.
In the 19th century, José María Castillo y Rada (1810-1888) was a prominent Ecuadorian statesman and politician who served as President of Ecuador from 1859 to 1865.
Throughout history, the surname Castillo has been associated with various place names and locations, such as Castillo de Locubín in the province of Jaén, Spain, and Castillo de Bayuela in the province of Toledo, Spain. These place names often reflected the presence of a castle or fortified structure in the area.
Demographics
Ancestry and ethnicity for Castillo
Among Census respondents with the surname Castillo, the largest self-reported group is Hispanic at 89.4%. The next largest groups are White (5.2%) and Asian/Pacific Islander (3.4%).
The bar chart below shows how Castillo 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 Castillo surname at the time of the 2020 Census, not any inherent property of the name itself.
- Hispanic or Latino89.4% · 206,850
- White5.2% · 11,958
- Asian and Pacific Islander3.4% · 7,898
- Black or African American0.8% · 1,942
- Two or more races0.6% · 1,368
- American Indian and Alaska Native0.6% · 1,331
Timeline
Historical Census data for Castillo
Castillo 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
#93
National surname rank
Recorded bearers 230,420
+64,947 bearers (+39.2%)
Per 100,000 78.11
Rank movement Up 42 places
2020
#94
National surname rank
Recorded bearers 231,347
+927 bearers (+0.4%)
Per 100,000 77.40
Rank movement Down 1 places
| Year | Rank | Count | Per 100K | Count change | Rank change |
|---|---|---|---|---|---|
| 2000 | #135 | 165,473 | 61.34 | First available Census row | First available Census row |
| 2010 | #93 | 230,420 | 78.11 | +64,947 bearers (+39.2%) | Up 42 places |
| 2020 | #94 | 231,347 | 77.40 | +927 bearers (+0.4%) | Down 1 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 Castillo 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 | #93 | #94 | -1.1% |
| Count | 230,420 | 231,347 | 0.4% |
| Per 100K | 78.11 | 77.40 | -0.9% |
Between the 2010 and 2020 Census, the number of Castillo bearers went from 230,420 to 231,347 (+0.4% change). The surname moved down 1 positions in the national ranking, going from #93 to #94.
Notable bearers
Famous people with the surname Castillo
FAQ
Castillo surname: questions and answers
How many people in the U.S. have the surname Castillo?
Name Census estimates that about 265,292 living Americans carry the surname Castillo. Using the current population baseline, that works out to roughly 1 in 1,292 residents.
How common is Castillo?
Castillo ranks #94 in the 2020 Census surname tables and is classified on this site as "Common." The Census recorded the name at a frequency of 77.40 per 100,000 residents, which is about 77 people out of every 100,000.
How many people with this surname were counted in the Census?
The raw 2020 Census file counted 231,347 people with the surname Castillo. That is different from the site's living-bearer estimate (265,292), which projects the surname's present-day count by applying the Census frequency rate to the current U.S. population.
What does 77.4 per 100,000 actually mean?
It is the Census Bureau's normalized frequency measure. A rate of 77.40 per 100,000 means that if you picked a random group of 100,000 U.S. residents, you would expect about 77 of them to have the surname Castillo.
Has Castillo become more or less common over time?
Between 2010 and 2020, the surname Castillo went from 230,420 recorded bearers to 231,347. That is an increase of 927 (+0.4%). In the national ranking it fell from #93 to #94.
What does the Census say about the background of Castillo?
Among Census respondents with the surname Castillo, the largest self-reported group is Hispanic at 89.4%. The next largest groups are White (5.2%) and Asian/Pacific Islander (3.4%). 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 Castillo in the 2020 Census, accounting for 89.4% (206,850 people in the source table).
What is the full ancestry breakdown?
Castillo appears across multiple self-reported groups in the Census data. The largest shares in the 2020 file are Hispanic (89.4%), White (5.2%), Asian/Pacific Islander (3.4%). 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 Castillo (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 Castillo mean?
A Spanish topographical surname referring to someone who lived near a castle or fortified building. 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 Castillo (77.40 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 Castillo?
If you just want to know how many people are called Castillo, HowManyOfMe.org gives you the headline number in one glance.