Meaning From Celtic origin meaning 'white' or 'fair', it is popular in the Irish language. A variant of Finn and Finley. Origin of Fionn Celtic , Irish Popular Middle Names Patrick Pronunciation 🔊 Listen Fionn FEE-onn Similar Names Finnegan Finley Aodhan Barry Fin Kenny Neil Finlay Findlay Shaye Year by Year Popularity of Fionn