How Many People Are Named Thelonious?
An estimated 444 people in the United States have the first name Thelonious. It is almost exclusively a male name. The average bearer is 20 years old, and Thelonious peaked in popularity in 2017 with 23 births that year.
Below you will find a full statistical profile of Thelonious as a first name in the United States, including gender data, a year-by-year popularity timeline going back to 1880, a decade breakdown, state-by-state birth registrations, and, when available, a 2020 Census snapshot showing who had the name at that point in time. You can also check how many people share the full name Thelonious paired with any surname.
Estimated Living Americans
444
About 1 in 771,969 people in the U.S.
Rarity
Very Rare
Predicted Gender
Male
100.0% confidence
Average Age
20
years old
Peak Year
2017
23 births
Total Registered
455
since 1880
Gender Distribution for Thelonious
Thelonious is almost exclusively a male name. Out of 455 total births registered, 100.0% were male.
Thelonious as a male name
Ranked #5,847 in 2024
16 male births in 2024
Peak: 2017 (23 births)
Thelonious in the 2020 Census
The 2020 Census recorded 362 people with the first name Thelonious, which placed it at #25,961 in the published first-name tables. This is a snapshot of people who already had the name in 2020. The estimated living count elsewhere on this page is different: it is a current estimate built from SSA birth records and age-based survival rates, so the two figures are not expected to match exactly.
Read this section as a snapshot of people who already had the name in 2020. The SSA charts elsewhere on this page are still the better way to see how the name rose, fell, or shifted across generations.
Gender in the 2020 Census
In the 2020 Census, Thelonious was recorded as predominantly male. Out of 362 people with this name in that snapshot, 98.9% were male and 1.1% were female. That is very close to the long-run birth pattern in SSA records, where the name is male 100.0% of the time.
Census Count
362
people with this name
Census Rank
#25,961
among Census first names
Frequency Rate
0.12
per 100,000 people
Recorded Race and Hispanic Origin in the 2020 Census
In the 2020 Census, the first name Thelonious was most commonly recorded among people who identified as White (36.59%). The next largest recorded groups were Black (33.88%) and Two or More Races (17.34%).
These percentages describe the people who had the first name Thelonious in the 2020 Census. They do not tell you the deeper meaning or origin of the name itself.
2020 Census demographic breakdown
Each row shows a recorded Census category for people with the first name Thelonious.
| Group | Share | Count |
|---|---|---|
| White | 36.59% | 135 |
| Black | 33.88% | 125 |
| Two or More Races | 17.34% | 64 |
| Hispanic | 8.67% | 32 |
| Asian and Pacific Islander | 2.44% | 9 |
| American Indian and Alaska Native | 1.08% | 4 |
The Census published separate sex and race/origin tables for first names, so their total counts can differ slightly for the same name. That is why the race section focuses on the demographic mix rather than repeating a second headline count.
Thelonious: Popularity Over Time
SSA records for Thelonious span from the 1960s to the 2020s, covering 7 decades of naming data. The most popular decade for this name was the 2010s, when 170 babies were registered. While Thelonious is less common than at its peak in the 2010s, it remains a well-established name with steady registrations.
Thelonious by Decade
How has Thelonious 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.
Thelonious by State
Thelonious + Last Name Combinations
How many people share a full name with Thelonious as the first name? Click a combination below to see the estimate, or search any pairing.
Names Similar to Thelonious
Other first names starting with T with a similar number of bearers.
Thelonious: Questions and Answers
How many people in the U.S. are named Thelonious?
We estimate approximately 444 people named Thelonious 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 771,969 Americans share this first name.
Is Thelonious a common name?
Thelonious is classified as "Very Rare" and is more popular than 83.4% of all first names in the SSA database. A total of 455 births have been registered with this name since 1880.
When was Thelonious most popular?
Thelonious reached peak popularity in 2017, when 23 babies were given this name. The average age of a living person named Thelonious is approximately 20 years old, reflecting when the name was most commonly given.
How common was Thelonious in the 2020 Census?
The 2020 Census recorded 362 people with the first name Thelonious. That placed it at #25,961 in the published Census first-name tables, or 0.12 people per 100,000.
Why is the Census count different from the living estimate?
Because they measure different things. The Census number is a count of people with the name in 2020. The living estimate is a current model based on SSA birth records and survival rates, so it aims to estimate how many people with the name are alive now.
What does the SSA popularity chart show?
The popularity chart tracks birth registrations, not people currently alive. It shows how often Thelonious was given to babies from 1880 through 2024, which is why it is the best tool on the page for seeing long-run naming trends.
What does the Census say about the gender split for Thelonious?
In the 2020 Census snapshot, Thelonious was recorded as predominantly male. The published split was 98.9% male and 1.1% female.
What does the Census say about the background of people named Thelonious?
In the 2020 Census, the first name Thelonious was most commonly recorded among people who identified as White (36.59%). The next largest recorded groups were Black (33.88%) and Two or More Races (17.34%). These percentages describe the people who had the name in the 2020 Census, not the deeper meaning or origin of the name itself.
Why can the Census sex total and race total differ slightly?
The Census published separate first-name tables for sex and for race and Hispanic origin. Those totals can differ slightly for the same name, so the page uses them as two related snapshots rather than treating them as perfectly interchangeable counts.
Does every first name have Census demographic data?
No. The public Census first-name tables only include names that met the Bureau's publication rules. That means some names on this site will have SSA history but no published Census demographic snapshot.
Is Thelonious a male name?
Thelonious is predominantly male. 100.0% of people with this name are male. See the gender breakdown above for full details.
Why can Thelonious have a lot of living bearers even if it is not trendy now?
Because a name can build up a large population over many decades. Thelonious peaked in 2017, and the average living bearer is about 20 years old, so a name can still have millions of living bearers even after it stops feeling current for newborns.
How many Thelonious Smiths are there?
To find how many people share a specific full name, we combine first name and surname frequencies. Try: Thelonious Smith, Thelonious Johnson, Thelonious 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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