Irish form of Una, possibly meaning 'lamb' or 'unity'; also used in Finnish culture as a given name.
Oona is the anglicized form of the Irish *Úna* (also spelled Oonagh or Una), a name whose etymology is genuinely contested — scholars have linked it to the Old Irish word for "lamb," to the Latin *una* ("one" or "unity"), and to a possible Proto-Celtic root meaning "river" or "pure." In Irish mythology, Úna appears as a queen of the fairies — variously the wife of Finvarra, the fairy king of Connacht — a figure of otherworldly beauty associated with the liminal spaces between the human and spirit worlds. The name thus carries ancient Celtic magic at its core, rooted in a tradition of storytelling older than written Irish literature.
In the twentieth century, Oona achieved a particular romantic fame through Oona O'Neill — daughter of playwright Eugene O'Neill — who married Charlie Chaplin at eighteen when he was fifty-four, remaining his devoted companion until his death in 1977. Their story was controversial but also, by all accounts, genuinely loving. Their granddaughter Oona Chaplin, the actress known for her role in *Game of Thrones*, carries the name into a new generation with considerable poise.
The spelling Oona has a clean, open quality on the page — two vowels, one consonant, a name that almost sings itself — and its Irish roots give it substance without requiring any particular Gaelic heritage to wear it well. It is rare enough to feel distinctive, familiar enough to wear comfortably.