brennan

Brennan is a surname of Irish origin, traditionally derived from the Gaelic Ó Braonáin (descendant of Braonán) or, less commonly, Ó Bréanáin. The name is associated with several historic kin groups in Ireland and has long been carried by families across Munster and Leinster. Through Irish emigration, Brennan spread to Britain, North America, Australia, and beyond, and remains a common surname among people of Irish heritage.

As a given name, Brennan has gained usage in English-speaking countries in the late 20th century, often chosen for its connection to the surname tradition. It is used for both boys and girls in contemporary naming practices, though it originated as a masculine given name in some contexts.

Variants and related spellings reflect Anglicization and regional pronunciation, including Brenan and Brennen. The name may appear in historical records with alternative spellings, which can reflect local dialects or transcription practices.

Numerous individuals bearing the surname Brennan have achieved prominence in politics, sports, the arts, and academia, and the name appears in fiction and media. Today Brennan remains common in Ireland and in countries with large Irish diasporas, including the United States, Canada, the United Kingdom, and Australia.