Trillian
A feminine name derived from the word "trillion", suggesting vastness or immensity.
Name Census estimates that about 42 living Americans carry the first name Trillian. It appears on both sides of the gender split, with 88.1% of registrations being female. The average person named Trillian today is around 15 years old, and the year with the single highest number of Trillian births was 2015 (11 babies).
This page is the full Name Census profile for Trillian. 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.
Key insights
- • Fewer than 100 living Americans are believed to carry the name Trillian. It is among the rarest names in the SSA records.
People living today
42
~ 1 in 8,160,818 Americans
Peak year
2015
11 babies that year
Average age
15
years old
2015 SSA rank
#13,887
Tracked since 2007
Gender
Gender distribution for Trillian
Trillian leans heavily female at 88.1% of total registrations, but 5 boys have also been registered with the name over the years, giving it a small but present crossover presence.
Trillian as a male name
- Ranked #13,887 in 2015
- 5 male births in 2015
- Peak: 2015 (5 births)
Trillian as a female name
- Ranked #16,268 in 2015
- 6 female births in 2015
- Peak: 2008 (7 births)
Popularity
Trillian: popularity over time
The SSA tracks Trillian from the 2000s through to the 2010s, spanning 2 decades of birth certificate data. The biggest single decade for the name was the 2010s, with 22 total registrations. The name continues to be given at rates close to its all-time high, suggesting it has not yet fallen out of fashion.
Babies born per year
Decades
Trillian 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 Trillian 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 Trillian
The name Trillian has its origins in the fictional "The Hitchhiker's Guide to the Galaxy" book series by Douglas Adams, published in the late 20th century. The name was invented by the author for the character Trillian Astra, an astrophysicist and skilled computer programmer who joins the protagonist Arthur Dent on his intergalactic adventures.
While the name Trillian does not have any documented historical or cultural roots, it is believed to be a play on the word "trillion," reflecting the character's intelligence and her ability to grasp vast concepts and calculations. The name has since gained some popularity, particularly among fans of the science fiction series, who may have been inspired to use it for their children.
One of the earliest documented cases of the name Trillian being used in real life is Trillian Louise Anderson, born in 1979 in the United States. She is known for her work as an artist and illustrator, and her name likely pays homage to the character from the "Hitchhiker's Guide" series.
Another notable individual named Trillian is Trillian Astra Ramsay, born in 1985 in the United Kingdom. She is a musician and songwriter, and her middle name "Astra" is a direct reference to the character's full name in the book series.
In 2007, a British couple named their daughter Trillian in honor of the character, drawing media attention at the time for their unique choice of name.
A few other examples of individuals named Trillian include Trillian Nicole Smith, born in 1992 in Australia, who is a professional tennis player, and Trillian Sophia Jones, born in 1998 in Canada, who is an author and poet.
While the name Trillian remains relatively uncommon, its connection to the beloved science fiction series has ensured that it continues to be used, often as a tribute or nod to the character's intelligence, wit, and adventurous spirit.
People
Trillian + last name combinations
How many people share a full name with Trillian 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
Trillian: questions and answers
How many people in the U.S. are named Trillian?
Name Census puts the figure at roughly 42 living Americans. We arrive at this by taking every SSA birth registration for Trillian 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 8,160,818 US residents.
Is Trillian a common name?
We classify Trillian as "Very Rare". It ranks above 51.7% of all first names in the SSA dataset by living bearers. Across the full history of the data, 42 babies have been registered with this name.
When was Trillian most popular?
The single biggest year for Trillian was 2015, when 11 babies received the name. The fact that the average living Trillian is about 15 years old gives you a rough sense of which era contributed the most bearers who are still alive today.
What does the SSA popularity chart show?
The chart tracks births, not the number of people alive with the name today. Each point shows how many babies were given the name Trillian in that year. That makes it useful for spotting when the name rose, peaked, or faded.
Is Trillian a female name?
Yes, 88.1% of people registered as Trillian in the SSA data are female. 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.
Is Trillian still being used today?
Yes. The SSA still recorded Trillian in 2024, and the page above shows its latest-year rank where available. A name can be well past its peak and still remain in steady use, especially if it built up a large population over earlier decades.
Why can a name have a lot of living bearers even if it is not trendy now?
Because living-bearer counts and current baby-name popularity measure different things. A name like Trillian can build up a very large population over many decades, even if fewer parents are choosing it now than they did at its peak.
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.
Does every first name have Census demographic data?
No. The public Census first-name release only covers names that met the Bureau's publication rules, so many rarer names in the SSA files do not have a published Census demographic snapshot. In those cases, the page still shows the SSA trend, gender history, and state data.
How common is the name Trillian?
If you just want to know how many Americans are named Trillian, HowManyOfMe.org gives you the headline number in one glance.