Caileen is of Scottish origin, derived from the Gaelic 'Cailinn', which means 'slender' or 'slim'. It's a unique and uncommon name that has gained some popularity in recent years. The name Caileen can be spelled in various ways, including Kaelen, Kaleen, Kaileigh, and other variants. However, the most common spelling is Caileen.
The name Caileen experienced fluctuations in popularity from the late 1980s to the mid-2010s, with a total of 139 babies given this name during that period. The most popular years for the name were 1992 and 2010, each with 10 births, while the least popular years were 1988 and 2006, with just 5 births each.