Meaning A boy's name of Gaelic origin, it means "Slender; Fair Form of Caelan." Origin of Kaelin Gaelic , Irish +-100%Zoom level changed to 1 Popular Middle Names Jaxsin Pronunciation 🔊 Listen Kaelin Similar Names Kaelan Kalen Keillan Kelden Kelle Keilan Keelan Keeland Kenneth Fin Year by Year Popularity of Kaelin