How Many People Are Named Thaddius?
An estimated 539 people in the United States have the first name Thaddius. It is almost exclusively a male name. The average bearer is 37 years old, and Thaddius peaked in popularity in 1989 with 18 births that year.
Below you will find a full statistical profile of Thaddius 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 Thaddius paired with any surname.
Estimated Living Americans
539
About 1 in 635,908 people in the U.S.
Rarity
Very Rare
Predicted Gender
Male
100.0% confidence
Average Age
37
years old
Peak Year
1989
18 births
Total Registered
593
since 1880
Gender Distribution for Thaddius
Thaddius is almost exclusively a male name. Out of 593 total births registered, 100.0% were male.
Thaddius as a male name
Ranked #13,965 in 2023
5 male births in 2023
Peak: 1989 (18 births)
Thaddius: Popularity Over Time
SSA records for Thaddius span from the 1910s to the 2020s, covering 12 decades of naming data. The most popular decade for this name was the 1980s, when 116 babies were registered. Thaddius has declined significantly from its peak in the 1980s. Recent registrations are a fraction of what they were at the name's height.
Thaddius by Decade
How has Thaddius 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.
Thaddius + Last Name Combinations
How many people share a full name with Thaddius as the first name? Click a combination below to see the estimate, or search any pairing.
Names Similar to Thaddius
Other first names starting with T with a similar number of bearers.
Thaddius: Questions and Answers
How many people in the U.S. are named Thaddius?
We estimate approximately 539 people named Thaddius 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 635,908 Americans share this first name.
Is Thaddius a common name?
Thaddius is classified as "Very Rare" and is more popular than 85.3% of all first names in the SSA database. A total of 593 births have been registered with this name since 1880.
When was Thaddius most popular?
Thaddius reached peak popularity in 1989, when 18 babies were given this name. The average age of a living person named Thaddius is approximately 37 years old, reflecting when the name was most commonly given.
Is Thaddius a male name?
Thaddius is predominantly male. 100.0% of people with this name are male. See the gender breakdown above for full details.
How many Thaddius Smiths are there?
To find how many people share a specific full name, we combine first name and surname frequencies. Try: Thaddius Smith, Thaddius Johnson, Thaddius 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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