Killian
Masculine
Killian is given to both — 16,219 boys and 615 girls since 1880. See Killian as a girl nameSee other names given to both
Killian is the English spelling of the Irish Cillian, a name carried out of Ireland by monks and later by emigrants. It traveled far: Saint Kilian, the seventh-century Irish missionary martyred at Würzburg, is still the patron saint of that German city, which is why the name has a long German life as well as an Irish one. Two syllables, one obvious pronunciation, and a spelling most Americans read correctly on the first try.
How old is the name Killian?
Killian first appears in US birth records in 1915 — 110 years ago. The typical Killian is a kid of about 8 — this name's wave is very recent. About 16,000 people named Killian are estimated to be alive in the US today.
When was the name Killian most popular?
Killian peaked in 2017, reaching #248 nationally. Today it ranks #417, 169 places below that high. See the whole 2017 chart.
Killian appears on these lists:
Works in Irish families too:
Where it comes from
From Ceallach to Killian
The story of Killian
The name begins as Cillian in early medieval Ireland, in the era when Irish monks were crossing into continental Europe. One of them, Kilian, reached Franconia in the seventh century and was killed at Würzburg; his cult made the name a permanent German fixture as Kilian, complete with a summer feast day still marked in the city. In Ireland the native form stayed in use and the anglicized Killian traveled to America with Irish families. France took up Killian and Kilian in the later twentieth century, which is part of why the name now looks at home in several languages at once.
Meaningscholars disagree
linked either to the Irish word for church or to a root meaning strife
One reading traces Cillian to Old Irish cell, 'church' or 'monastic cell', giving a sense of 'of the church' — fitting for a name spread by missionaries. The other traces it to the personal name Ceallach, whose own meaning is disputed between 'strife' and, again, 'church'. Scholars have not settled it, and both readings sit inside the same small cluster of early Irish words.
How the name formed
- Ceallach
- Cillian
- Kilian
- Killian
Related forms: Cillian · Kilian · Kilian · Kilián · Kilián · Kiliaan
Pronouncing Killian
KIL-ee-un
Three light syllables with the stress on the first. The Irish Cillian is said the same way, so switching spellings changes nothing you hear.
Nicknames for Killian
Moderate
What the data says
146 years of official birth records
The long climb, and where it stands now
The same years in position rather than babies
- First recorded
- 1915
- Most boys named
- 20171,506 — the highest on record
- Peak rank
- #248reached in 2017
- Change vs 2024
- −13.0%770 in 2025, from 885
Rank is a position, a count is a headcount, and they move independently — a name can hold its rank while the number of babies behind it falls. Source: U.S. Social Security Administration.
Killian in other languages
The same name elsewhere
- Cillian in Irish — same name
- Kilian in German — spelling variant
- Kilian in French — spelling variant
- Kilián in Hungarian — same name
- Kilián in Czech — same name
- Kiliaan in Dutch — same name
Strongest US states over the last decade: California, Texas, Florida.
Killians among us
people named Killian are estimated to be alive in the US today
About 1 boy in 2,218 born in 2025 was named Killian
Estimated from SSA birth records and published actuarial life tables. Method
Spellings of Killian
- #417
- Killian on the 2025 chart
- #246
- counting every spelling
The SSA counts spellings, not names. Killian went to 770 boys in 2025, but Kylian, Kilian and Kyllian and the rest below are the same name said out loud. Together the 5 spellings went to 1,428, which makes it the 246th most-given boys’ name of the year — 171 places above the chart.
About 1 boy in 1,196 born in 2025 was given one of these spellings — against 1 in 2,218 for Killian itself.
Spellings are grouped by a fixed rule that folds interchangeable English spellings of one sound (ck/k, ph/f, x/ks, a non-initial y for i) and keeps vowels apart, so Sean and Shawn stay separate names. It errs towards splitting: a family here is never larger than the truth. SSA national data, 2025. Method
Is it right for you
What happens to a name after it peaks
The Nickolas test
Every popular name lives one long story — a climb, a peak, a slow settling back. Killian's later chapters haven't been written yet, so we borrowed them: Nickolas climbed just as high around 1989, and its whole arc is on record. Line the two peaks up, and Nickolas's path sketches the road Killian is walking now.
Killian sits in the calm middle of the cycle — neither chasing a wave nor sliding off one. Middle-of-the-cycle names age slowly and predictably.
A scored estimate from 146 years of naming cycles — not a prophecy. Great names outlive statistics. How this is scored
Where Killian is headed
Killian should hold steady through 2030 — the curve is flat, and flat curves are the most predictable kind. Its history is short or jumpy, though, so read this as a sketch rather than a promise.
Low confidence — fitted on official counts through 2025.
A damped-trend projection of the official birth data — a sketch of momentum, not a promise. Every name's forecast, ranked.
Killian beside its neighbors
The names ranked closest to Killian in 2025, in babies rather than position — the bars are to scale.
US boys given each name in 2025.
The trade-off
- One pronunciation, stated by the spelling — people rarely need to be corrected twice.
- A documented line back to early medieval Ireland, with an unbroken German life through the saint of Würzburg.
- Works across Irish, German, French and Central European forms, all recognizable to an English speaker.
- Familiar in sound without being everywhere: a child is unlikely to share it with a classmate.
- The first four letters spell an English word, and children notice that sort of thing. It passes quickly for most, but it is the one thing worth saying aloud before you decide.
- Killian and Cillian now compete, and the Irish spelling has grown visible enough that you should expect to specify which one you mean — at the pediatrician, on forms, in email.
- Its American wave is recent, so most people carrying it are still young. That means fewer adult namesakes to point to, and a name that reads as contemporary rather than inherited.
Nobody names a baby alone.
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What they receive
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Killian
Masculine · #417 in the U.S.
Frequently asked
- How many Killians are there in the world?
- No country counts the world's names, so there is no worldwide figure — anyone quoting one is estimating. About 16,000 people named Killian are estimated to be alive in the US today.
- How do you spell Killian?
- Killian is the most-used spelling in US records — 770 of the 1,428 babies given the name in 2025. The others recorded are Kylian, Kilian, Kyllian and Kilyan.
- How popular is the name Killian in 2025?
- Killian ranks #417 among US boy names in 2025, with 770 babies given the name.
- How rare is the name Killian?
- About 1 in every 2,218 US boys born in 2025 was named Killian — 770 in all.
- Will my child share the name Killian with classmates?
- Killian will almost certainly be the only one in school.
Ranked beside Killian
Names sitting at a similar level of popularity right now.
Conrad#417 · Reed#417 · Rylan#416 · Kaysen#415 · Cayden#414 · Francis#420 · Hank#413 · Jaden#421
Looking for what else is popular rather than what resembles Killian? See the current top 100.
Choosing between Killian and another name?
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US figures from the Social Security Administration. 1880–2025. Data & methodology
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