Caitlin is the anglicised version of Caitlín, an Irish name that can be traced back to the Greek name Aikaterine (Αἰκατερίνη). It is associated with the Greek word katharos (καθαρός), meaning "pure". The Old French form of the name is spelled Cateline. Caitlin was popular in the 1990s and early 2000s, but its popularity has fallen since then.