Trillian
UnisexGirls' nameBoys' nameMeaning not yet documented
Trillian has been given to 42 babies in the U.S. since 2007. It was used fewer than 5 times in 2025, so it doesn't appear in the latest year's list — today it's a genuinely uncommon pick. Its peak year was 2008, with 7 recorded. It's used for both sexes: 88% girls, 12% boys all-time.
Babies named Trillian, 2015
1 in 617,000
Trillian over time, 1880–2025
Based on births in the U.S. Babies given the name each year. Hover the chart — or focus it and use the arrow keys — for any year. Gaps mean the name was given fewer than 5 times that year; these counts are unpublished.
Girls or boys — Trillian over time
In 2015, Trillian went to 55% girls and 45% boys.
A sex is only published in years it reached five applications, so a stretch at 0% or 100% means the other side stayed under that floor — not that it was never used.
How common is Trillian?
Trillian had fewer than 5 recorded uses in 2025, so these figures use 2015, the last year it was published.
- Among all babies, 2015
- 1 in 617,000
- 6 of 3,701,574 births
- Among girls only
- 1 in 297,000
- <0.01% of girls
- Rank, 2015
- Unranked
- Fewer than 5 uses
- Coin-flip room size
- 427,624 kids
- Even odds of a second one
Where Trillian sits on the popularity scale
Chance at least one other child shares the name
If the other children were drawn at random from the 2015 national name distribution. Real classrooms cluster by region and community, so treat these as a floor, not a ceiling.
Put another way: gather 427,624 children born in 2015 and it's an even bet that one of them is another Trillian. In a class of 30 the chance is Under 1%.
When Trillians were born
Half of everyone ever recorded as Trillian was born before 2009 — so the typical Trillian is around 16 today.
- Biggest decade
- 2000s
- 54.1% of all use
- Born in the last 25 years
- 100.0%
- A modern name
- Recorded since 1950
- 37
- People you could plausibly meet
2000s — 54.1% of all recorded uses (20).
Is Trillian rising or falling?
Rank movement and count movement can disagree — the number of distinct names in use keeps growing, so a name holding a steady count still slides down the list. Both are shown.
- Rank vs 1 year ago
- —
- Not ranked then
- Rank vs 5 years ago
- New entry
- Not ranked then
- Rank vs 10 years ago
- —
- Not ranked then
- Births vs 10 years ago
- —
- Not published both years
- Share of its own peak
- 0%
- Peak was 2008 (7)
- Years since peak
- 17
- Years
- Year-to-year steadiness
- Steady
- 11.9% average annual change
Spellings of Trillian
Trillian is not the most common spelling — Lillian is, with 82.5% against Trillian's <0.01%.
Grouped by closeness of spelling (up to two letter changes), same sex, with a floor on all-time use. It catches Sophia/Sofia and Aiden/Ayden, and misses spellings that sound alike but look different, like Sean and Shawn.
Trillian around the world
Where Trillian ranks in official birth records elsewhere in the world. Rankings only — the number of births isn’t comparable between places, so it isn’t shown.
- South Australia1982–1982#670in 1982
Popularity data from Consumer and Business Services (South Australia). CBS SA data under CC BY 4.0.
Trillian by the numbers
The raw record for each sex the name is used for.
As a girl's name
Names similar to Trillian
Matched on shared beginnings and endings, similar length, and comparable popularity.
Sibling names for Trillian
Names from the same era and popularity tier — the two things that make a sibling set feel deliberate — skipping lookalike spellings and shared initials.