Meaning Kellen is a Celtic name for a girl, it means slim, lean, and trim. Origin of Kellen Celtic , Irish Popular Middle Names Andrew, James, Jonathan, Joseph, Liam, Lou, Luke, Matthew, Michael, Noel Pronunciation 🔊 Listen Kellen KEL-len Similar Names Akhyar Viho Blaike Triston Atrus Arturs Galvyn Artie Tamunokuro Artturi Year by Year Popularity of Kellen