Brian O'Sullivan was born in county Cork, Ireland. On completing a degree at University College Cork, he went on to travel extensively. He is now based in New Zealand with his family but returns to Ireland on a regular basis.
Brian writes fiction that incorporates strong elements of Irish culture, language, history and mythology. These include literary short stories (The Irish Muse collection), mystery thrillers (The Beara Trilogy) and contemporary versions of the Fionn mac Cumhaill/ Fenian legends (The Fionn mac Cumhaill Series and the Irish Woman Warrior Series).
Although he writes predominantly for an Irish audience, Brian's unique style and humour has meant that his books have become firm favorites of readers all around the world.
The sixth book in the the Fionn mac Cumhaill Series (Fionn: The Betrayal) was released in April 2025.
The author is currently working on the next book in the Beara Series.