O'Brien is an Irish surname and given name, derived from the Gaelic Ó Briain sept name, which means "descendant of Brian" or "of the descending sun". It was borne by several early Irish kings, includingBrian Boru, who united Ireland in the 11th century. The O'Brien clan was historically based around Thomond, now known as County Clare in western Ireland.
In modern times, O'Brien has been adopted as a given name for both boys and girls. It gained popularity in English-speaking countries during the 20th century. Some notable individuals with the name O'Brien include Australian actress Cate Blanchett, American actor Patrick O'Brian (whose given name was John), and Irish playwright George Bernard Shaw.
The name O'Brien is often associated with Ireland's rich history and culture. It is considered a strong, distinctive name that carries a sense of heritage and tradition. While it is not particularly popular as a given name, it remains a well-known and respected surname throughout the world.
The name O'Brien experienced peaks in popularity during the late 1980s and early 1990s, with a total of 209 births recorded between 1921 and 2022.