Finnegan is an Irish surname, Ó Fionnagáin, that means "fair" or "white-haired", from the Gaelic fionn, the same root as Finn. James Joyce's Finnegans Wake and the old ballad behind it gave the name a mischievous, literary flavor, and parents like that it comes with the nickname Finn built in. Finnegan entered the US top 1000 in 2005, peaked at number 378 in 2021 and ranks number 526 in 2025.