An Irish form of Katherine, ultimately from Greek and commonly linked with the meaning "pure."
Caitlyn is an anglicized spelling of Caitlín, the Irish form of Katherine — a name whose ultimate origins have been debated by scholars for centuries. Most trace it back to the Greek Aikaterinē, possibly linked to the goddess Hecate or to the Greek word katharos, meaning "pure." The name entered Ireland through the Norman and ecclesiastical influence of the medieval period, where it was absorbed into the Irish language's phonetic patterns and emerged as Caitlín — pronounced roughly "KAHT-leen" in Irish, a sound that the anglicized spellings Kathleen, Caitlin, and Caitlyn have each attempted to capture in their own way.
In the Irish literary and nationalist tradition, Caitlín takes on profound symbolic weight. B. Yeats and Lady Gregory's 1902 play of the same name — represents Ireland itself as an old woman transformed into a young queen, calling young men to sacrifice themselves for her freedom.
This allegorical personification made the name indelibly associated with Irish identity, sacrifice, and the romantic nationalism of the Celtic Revival. The name appears throughout Irish poetry and fiction as a marker of authenticity and belonging. The spelling Caitlyn emerged in the late twentieth century as a further anglicization, joining Kaitlyn, Katelyn, and other phonetic variants in the landscape of English-language naming.
Its cultural profile shifted significantly in 2015 when Caitlyn Jenner's public transition placed the name at the center of international conversations about identity, visibility, and personal transformation — giving it new layers of meaning for many families who choose it today. Across all its associations, Caitlyn remains a name of genuine depth: part ancient Irish heritage, part living cultural moment.