Meaning A boy's name of Gaelic origin, it means "Slender; Fair Form of Caelan." Origin of Kalen Gaelic , Irish Popular Middle Names Amier, Edward, Jackson, James, Joseph, Kristofer, Liam Pronunciation 🔊 Listen Kalen KAL-en Similar Names Kaelan Kaelin Keillan Kelden Kelle Keilan Keelan Keeland Kenneth Fin Year by Year Popularity of Kalen