Caitlin
Meaning
“Irish form of Katherine, traditionally pure”
The story
Caitlin is the Irish Caitlín, the island's own form of Katherine, traditionally pure, and Americans adopted the spelling while keeping the anglicized pronunciation KATE-lin rather than the Irish kotch-LEEN, a compromise Ireland has learned to smile about. It appears in the US record in the 1950s and climbs to a peak across the 1990s and 2000s, trailed by an army of phonetic spellings, Kaitlyn, Katelyn, Kaitlin, Katelynn, that collectively outnumbered the original many times over. The fall since has been steep across the entire family. Caitlin remains the version closest to the source, one respelling from Ireland instead of three, and its arc is the textbook case of a borrowed classic gradually conquered by its own echoes. What survives the family's decline is the form closest to the Irish original, which leaves the deepest history under the version still standing.
Caitlin around the world
One shared root links 26 names across 8 languages.
Shared root: from Greek Aikaterine, linked since early Christian times to katharos "pure", though the name's true origin predates that folk etymology
The constellation
19 more branches of this family
Popularity, 1890–2024
Shape drawn from US Social Security baby-name records. Caitlin peaked in the 1990s and the 2000s in nearly equal measure.
How the spellings raced
Across these spellings, Kaitlyn led in the group’s busiest decade, the 1990s. So far in the 2020s, Kaitlyn leads.
Decade totals from US Social Security birth registrations. Every line uses the same scale. The 2020s covers 2020–2025.
When you meet Caitlin
Most people given the name Caitlin in the United States were born between 1980 and 2009. The Caitlin you meet today is most often in her 20s or 30s.
Estimated from US Social Security birth registrations and typical lifespans; a rough guide, not a rule.
The Caitlin deep dive
Whether you’re naming a baby or exploring your own name’s history, this is a personal letter, not a list: where Caitlin truly comes from, how it traveled, and what a century of records reveals. If you have grown a tree on nametree, it also considers how Caitlin fits with your family’s names and surname.
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