Meaning Largely used in Scottish languages, Niall means 'champion', 'cloud' or 'passionate'. Origin of Niall Celtic , Irish Popular Middle Names Thomas, Emerson, Jacob, Nicolas Pronunciation 🔊 Listen Niall NAYL Similar Names MacNaughton MacNeill Nemausus Kenrick Neal Carmichail Ceannfhionn Cearbhallan Nicholaus Mattias Year by Year Popularity of Niall