How Many People Are Named Ildefonso?
An estimated 330 people in the United States have the first name Ildefonso. It is almost exclusively a male name. The average bearer is 46 years old, and Ildefonso peaked in popularity in 1976 with 16 births that year.
Below you will find a full statistical profile of Ildefonso as a first name in the United States, including gender data, a year-by-year popularity timeline going back to 1880, a decade breakdown, and state-by-state birth registrations. You can also check how many people share the full name Ildefonso paired with any surname.
Estimated Living Americans
330
About 1 in 1,038,650 people in the U.S.
Rarity
Very Rare
Predicted Gender
Male
100.0% confidence
Average Age
46
years old
Peak Year
1976
16 births
Total Registered
392
since 1880
Gender Distribution for Ildefonso
Ildefonso is almost exclusively a male name. Out of 392 total births registered, 100.0% were male.
Ildefonso as a male name
Ranked #13,067 in 2022
5 male births in 2022
Peak: 1976 (16 births)
Ildefonso: Popularity Over Time
SSA records for Ildefonso span from the 1910s to the 2020s, covering 12 decades of naming data. The most popular decade for this name was the 1980s, when 76 babies were registered. Ildefonso has declined significantly from its peak in the 1980s. Recent registrations are a fraction of what they were at the name's height.
Ildefonso by Decade
How has Ildefonso tracked across different eras? The table below groups all SSA birth registrations into 10-year periods, with separate male and female counts. The colored bar shows each decade's share relative to the peak.
Ildefonso by State
Ildefonso + Last Name Combinations
How many people share a full name with Ildefonso as the first name? Click a combination below to see the estimate, or search any pairing.
Names Similar to Ildefonso
Other first names starting with I with a similar number of bearers.
Ildefonso: Questions and Answers
How many people in the U.S. are named Ildefonso?
We estimate approximately 330 people named Ildefonso are alive in the United States today. This is based on SSA birth records from 1880 to 2024, adjusted for mortality using CDC life tables. About 1 in 1,038,650 Americans share this first name.
Is Ildefonso a common name?
Ildefonso is classified as "Very Rare" and is more popular than 80.3% of all first names in the SSA database. A total of 392 births have been registered with this name since 1880.
When was Ildefonso most popular?
Ildefonso reached peak popularity in 1976, when 16 babies were given this name. The average age of a living person named Ildefonso is approximately 46 years old, reflecting when the name was most commonly given.
Is Ildefonso a male name?
Ildefonso is predominantly male. 100.0% of people with this name are male. See the gender breakdown above for full details.
How many Ildefonso Smiths are there?
To find how many people share a specific full name, we combine first name and surname frequencies. Try: Ildefonso Smith, Ildefonso Johnson, Ildefonso Williams. You can also search any combination on our homepage.
Where does this data come from?
Our estimates use Social Security Administration birth records (1880 to 2024), adjusted for survival using CDC 2023 life tables broken down by sex. The U.S. population figure (342,754,338) is from the Census Bureau's July 2025 estimate. Full methodology.
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