Meaning Brennan is a boys name of Celtic origin , its meaning is 'descendent of 'Braonán'. Origin of Brennan Celtic , Irish +-100%Zoom level changed to 1 Popular Middle Names James, Michael, Thomas, Lee, Mark, Matthew, Kade, Keith, Lamonte, Patrick Pronunciation 🔊 Listen Brennan BREHN-ahN Similar Names Barry Powell Artek Kyle Ryan Arth Artis Arty Atre Artturi Year by Year Popularity of Brennan