Thaddius
A masculine name of Aramaic origin meaning "heart" or "courageous".
Name Census estimates that about 539 living Americans carry the first name Thaddius. The name is used almost exclusively for boys. The average person named Thaddius today is around 37 years old, and the year with the single highest number of Thaddius births was 1989 (18 babies).
This page is the full Name Census profile for Thaddius. Below you will find a gender breakdown showing how the name splits between male and female registrations, a year-by-year popularity chart stretching back to 1880, decade-level totals, the top US states for this name, its meaning and etymology, and a set of frequently asked questions with data-backed answers.
People living today
539
~ 1 in 635,908 Americans
Peak year
1989
18 babies that year
Average age
37
years old
2023 SSA rank
#13,965
Tracked since 1916
Popularity
Thaddius: popularity over time
The SSA tracks Thaddius from the 1910s through to the 2020s, spanning 12 decades of birth certificate data. The biggest single decade for the name was the 1980s, with 116 total registrations. Usage has dropped considerably from its 1980s peak. The most recent decade brought in only a fraction of the registrations that the name once attracted.
Babies born per year
Decades
Thaddius by decade
The table below breaks the full SSA timeline into ten-year windows. Each row shows how many male and female babies were given the name Thaddius during that decade, along with a combined total. This is useful for spotting eras where the name surged or retreated.
Origin
Meaning and history of Thaddius
The name Thaddius has its origins in the Aramaic name Taddai, which is thought to be derived from the word "thadd" meaning "breast" or "courageous." It is a variant of the Hebrew name Judah, which means "praised."
The name first appeared in the New Testament of the Bible, where Thaddeus (or Thaddaeus) was one of the twelve apostles of Jesus Christ. He is sometimes identified with Jude the Apostle, who is credited with writing the Epistle of Jude in the New Testament.
One of the earliest recorded individuals with the name Thaddius was Thaddius of Edessa, a Syrian philosopher and theologian who lived in the 4th century AD. He is known for his work in preserving and translating Greek philosophical and scientific texts into Syriac.
In the Middle Ages, there was a Saint Thaddeus (or Thadee) who was a Christian missionary and is recognized as the Apostle of Armenia. He is said to have been martyred in the city of Karin (now known as Erzurum, Turkey) in the 1st century AD.
Another notable figure with this name was Thaddius Hayek (1629-1704), a Lebanese Maronite philosopher, theologian, and writer. He is known for his works on logic, metaphysics, and theology, and his efforts in promoting education in the Maronite community.
In the 18th century, there was Thaddius Kosciuszko (1746-1817), a Polish military leader and national hero who played a significant role in the American Revolutionary War and the Polish-Lithuanian Commonwealth's struggle for independence.
In more recent times, the name Thaddius has been less common, but it has been used as a variant of the names Theodore and Thaddeus. It has maintained its association with courage, strength, and religious significance.
People
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.
Related
Other names starting with T
Other first names starting with T with a similar number of bearers.
FAQ
Thaddius: questions and answers
How many people in the U.S. are named Thaddius?
Name Census puts the figure at roughly 539 living Americans. We arrive at this by taking every SSA birth registration for Thaddius going back to 1880 and adjusting each cohort for expected survival using CDC actuarial life tables. The result is an age-weighted living-bearer count, not a raw birth total. That works out to about 1 in 635,908 US residents.
Is Thaddius a common name?
We classify Thaddius as "Very Rare". It ranks above 85.3% of all first names in the SSA dataset by living bearers. Across the full history of the data, 593 babies have been registered with this name.
When was Thaddius most popular?
The single biggest year for Thaddius was 1989, when 18 babies received the name. The fact that the average living Thaddius is about 37 years old gives you a rough sense of which era contributed the most bearers who are still alive today.
Is Thaddius a male name?
Yes, 100.0% of people registered as Thaddius in the SSA data are male. You can see the full per-sex comparison in the gender distribution section above, which includes the latest year rank, birth count, and peak year for each sex.
Where does this data come from?
First-name figures come from the Social Security Administration's national baby name files, which cover every name on a birth certificate from 1880 to 2024. Living-bearer estimates layer in CDC actuarial life tables broken out by sex to account for mortality. The population baseline (342,754,338) is the Census Bureau's latest national estimate. You can read the full calculation on our methodology page.