Meaning Derived from Kealan of Celtic origin meaning 'slender one'. Origin of Kielan Celtic , Irish +-100%Zoom level changed to 1 Popular Middle Names Pronunciation 🔊 Listen Kielan KEE-lan Similar Names Kylan Barry Kule Kyle Kaylem Cailin Gervase Keelen Keelan Kaydon Year by Year Popularity of Kielan