Cailean is a unisex given name of Scottish origin, derived from the Gaelic word 'caol' meaning 'slender'. It gained prominence during the Victorian era and has since become more commonly used in English-speaking countries. The name Cailean typically does not have any associated nickname variants or diminutives.
The name Cailean experienced fluctuations in popularity over time, with peaks occurring in the mid-90s and again around the mid-2000s.