KILLEEN Family History
This ancient Irish surname has two possible origins. Firstly, it may be an Anglicized form of the Gaelic personal name "Cillin", a diminutive of "Ceallach" which means "bright-headed". The name was borne by various early Irish saints, including the leader of a 7th Century mission to Franconia and Thuringia, hence the popularity of the given name Kilian in medieval central Europe, from which several surnames are derived. The second possibility is as an Anglicization of the Gaelic "Mac Coilin" which is composed of the elements "mac" meaning son of, with the personal name Colin, which derives from the Celtic "Cailean" meaning a young hound.