Oonagh
pronounced OU-naFrom the Irish word uan “a lamb” or may come from the Latin una meaning “one,” hence it is sometimes translated as “Unity.”
More about Oonagh7 Irish names beginning with O for girls and boys, with what each one means and how to say it.
Updated September 2026
Of the 7 Irish names starting with O here, 3 are for girls and 4 for boys. The ones readers look up most are Oisin, Owen and Orla.
The O names on this page that the most babies were given in 2025, by the Central Statistics Office’s ranking (girls and boys are ranked separately).
From the Irish word uan “a lamb” or may come from the Latin una meaning “one,” hence it is sometimes translated as “Unity.”
More about OonaghOrla in Irish is Orlaith, pronounced OR-la, meaning “golden princess.”
More about OrlaOrlaith comes from the Irish Órlaith (older Órfhlaith), from ór “gold” and flaith “ruler, prince,” which is read as “princess” in women’s names, so “golden princess.”
More about OrlaithAll variants of odhra meaning “dark haired.” Seventeen saints have used the name and Odhran, abbot of Meath, was one of the 12 devotees who accompanied St. Columba to Iona.
More about OdhranOdran in Irish is Odhran, pronounced O-ran, meaning “dark-haired.”
More about OdranThe son of the legendary warrior Fionn Mac Cool and the goddess Sive. His mother was turned into a deer by the Dark Druid and she reared him in the forest until he was seven years old.
More about OisinOwen in Irish is Eoghan, pronounced O-in, meaning “born of the yew tree.”
More about Owen