How Many People Are Named Thadius?
An estimated 476 people in the United States have the first name Thadius. It is almost exclusively a male name. The average bearer is 34 years old, and Thadius peaked in popularity in 1974 with 19 births that year.
Below you will find a full statistical profile of Thadius 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 Thadius paired with any surname.
Estimated Living Americans
476
About 1 in 720,072 people in the U.S.
Rarity
Very Rare
Predicted Gender
Male
100.0% confidence
Average Age
34
years old
Peak Year
1974
19 births
Total Registered
511
since 1880
Gender Distribution for Thadius
Thadius is almost exclusively a male name. Out of 511 total births registered, 100.0% were male.
Thadius as a male name
Ranked #10,760 in 2024
7 male births in 2024
Peak: 1974 (19 births)
Thadius: Popularity Over Time
SSA records for Thadius span from the 1920s to the 2020s, covering 9 decades of naming data. The most popular decade for this name was the 1970s, when 118 babies were registered. Thadius has declined significantly from its peak in the 1970s. Recent registrations are a fraction of what they were at the name's height.
Thadius by Decade
How has Thadius 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.
Thadius + Last Name Combinations
How many people share a full name with Thadius as the first name? Click a combination below to see the estimate, or search any pairing.
Names Similar to Thadius
Other first names starting with T with a similar number of bearers.
Thadius: Questions and Answers
How many people in the U.S. are named Thadius?
We estimate approximately 476 people named Thadius 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 720,072 Americans share this first name.
Is Thadius a common name?
Thadius is classified as "Very Rare" and is more popular than 84.1% of all first names in the SSA database. A total of 511 births have been registered with this name since 1880.
When was Thadius most popular?
Thadius reached peak popularity in 1974, when 19 babies were given this name. The average age of a living person named Thadius is approximately 34 years old, reflecting when the name was most commonly given.
Is Thadius a male name?
Thadius is predominantly male. 100.0% of people with this name are male. See the gender breakdown above for full details.
How many Thadius Smiths are there?
To find how many people share a specific full name, we combine first name and surname frequencies. Try: Thadius Smith, Thadius Johnson, Thadius 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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