Cailin
Feminine · “girl”
Cailin is overwhelmingly a girls’ name — 3,713 girls against 30 boys since 1880.
Cailin is the Irish word for a girl. Not a name — the noun. It is what an Irish speaker calls any girl at all, which is why Ireland does not use it as a name and America does. Colleen is the same word, spelled by ear a century earlier.
How old is the name Cailin?
Cailin first appears in US birth records in 1968 — 57 years ago. The typical Cailin alive today was born around 2002, making them about 23 years old. About 3,700 people named Cailin are estimated to be alive in the US today.
When was the name Cailin most popular?
Cailin peaked in 1998, reaching #1161 nationally. Today it ranks #11932, 10,771 places below that high. See the whole 1998 chart.
Lists built from the same records:
Where it comes from
From caile to Cailin
The story of Cailin
Irish America invented a set of names that Ireland has never used. Colleen is the word for a girl. Erin is a poetic form of the name of the country, in a grammatical case that means of Ireland rather than Ireland. Shannon is a river. Kelly as a woman's name is a surname. Every one of them is perfectly real as an American name and would raise an eyebrow in Dublin, which is not a criticism of either place: emigrant communities routinely preserve, invent and reshape more freely than the country they left. Cailin is the Irish spelling of Colleen, brought back across by American parents who wanted the older-looking version of a name their own country had made.
Meaning
girl
Irish cailin, a girl or young woman, from caile, a country woman, with a diminutive ending. It is a common noun, not a personal name, in Ireland. English speakers heard it in songs and conversation, took it for a name, and it became one in America without ever becoming one at home.
How the name formed
- caile
- cailin
- Cailin
Related forms: cailin
Pronouncing Cailin
KAY-lin
Two syllables, stress on the first, in American use. The Irish word is said kah-LEEN, with the weight at the end and a long second vowel, which is where Colleen comes from and is a noticeably different word.
Nicknames for Cailin
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
- 1968
- Most girls named
- 2003164 — the highest on record
- Peak rank
- #1161reached in 1998
- Change vs 2024
- −50.0%7 in 2025, from 14
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.
Cailin in other languages
The same name elsewhere
- cailin in Irish — related form
Strongest US states over the last decade: California, Texas, New York.
Cailins among us
people named Cailin are estimated to be alive in the US today
About 1 girl in 229,610 born in 2025 was named Cailin
Estimated from SSA birth records and published actuarial life tables. Method
Spellings of Cailin
- #11932
- Cailin on the 2025 chart
- #447
- counting every spelling
The SSA counts spellings, not names. Cailin went to 7 girls in 2025, but Kaylynn, Kaylin and Kailyn and the rest below are the same name said out loud. Together the 12 spellings went to 616, which makes it the 447th most-given girls’ name of the year — 11,485 places above the chart.
and 4 rarer spellings.
About 1 girl in 2,609 born in 2025 was given one of these spellings — against 1 in 229,610 for Cailin 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 Sheryle test
Every popular name lives one long story — a climb, a peak, a slow settling back. Cailin's later chapters haven't been written yet, so we borrowed them: Sheryle climbed just as high around 1947, and its whole arc is on record. Line the two peaks up, and Sheryle's path sketches the road Cailin is walking now.
Cailin 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
Cailin beside its neighbors
The names ranked closest to Cailin in 2025, in babies rather than position — the bars are to scale.
US girls given each name in 2025.
The trade-off
- A settled meaning in a living language, checkable in any Irish dictionary.
- Two syllables that everyone reads correctly on sight.
- It serves either child, and the records show both.
- Caitlin, Kaitlyn and Caitlyn are all commoner and this will be read as one of them.
- In Ireland it is a common noun rather than a name, and Irish speakers will say so.
- The Irish and American pronunciations are quite different, which matters if the family is Irish.
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What they receive
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Cailin
Feminine · #11932 in the U.S.
Frequently asked
- How many Cailins are there in the world?
- No country counts the world's names, so there is no worldwide figure — anyone quoting one is estimating. About 3,700 people named Cailin are estimated to be alive in the US today.
- How do you spell Cailin?
- Cailin is one of 8 recorded spellings. Kaylynn is the more common one — 134 births in 2025 against 7 for Cailin.
- How popular is the name Cailin in 2025?
- Cailin ranks #11932 among US girl names in 2025, with 7 babies given the name.
- How rare is the name Cailin?
- About 1 in every 229,610 US girls born in 2025 was named Cailin — 7 in all.
- Will my child share the name Cailin with classmates?
- Cailin will almost certainly be the only one in school.
Ranked beside Cailin
Names sitting at a similar level of popularity right now.
Vina#11932 · Retta#11932 · Missouri#11932 · Iola#11932 · Eddie#11932 · Thomas#11932 · Louetta#11932 · Elvina#11932
Looking for what else is popular rather than what resembles Cailin? See the current top 100.
Choosing between Cailin and another name?
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US figures from the Social Security Administration. 1880–2025. Data & methodology
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