Art MacBaron O'Neill

Art MacBaron O'Neill (Irish: Art mac Baron Ó Néill; before 1550 – 28 November 1618) was an Irish landowner and soldier who fought in the Nine Years' War. He is sometimes referred to as Arthur O'Neill.

Early life Art MacBaron O'Neill was born into the O'Neill clan, the ruling Gaelic Irish noble family of Tír Eoghain in Ulster. He was the son of Matthew O'Neill, 1st Baron Dungannon. His epithet "MacBaron" referred to his father's title ("son of the Baron"). His father's other children were Brian O'Neill, Cormac MacBaron O'Neill and Hugh O'Neill, Earl of Tyrone.

It is clear that Hugh and Brian were sons of Matthew's wife Siobhán Maguire, but the identity of Art and Cormac's mother is not entirely clear. John O'Hart stated that Cormac MacBaron and Art MacBaron were illegitimate. Hiram Morgan and Jerrold Casway similarly refer to Art as Hugh's half-brother.

Brian was Matthew's eldest son.

Art did not take part in the Flight of the Earls. It is not clear if he stayed in Ireland by choice or was deserted by Hugh. Hugh's departure may have been so quick that Art was not able to respond.

Art MacBaron O'Neill died on 28 November 1618.

Children Art MacBaron O'Neill was married at least three times. His first wife was a daughter of Brian McPhelim O'Neill. Another wife was Rose, daughter of Turlough Luineach O'Neill, who survived Art by at least seven years. His third wife was the daughter of Hugh Conallach O'Reilly of Breifne.

Sources indicate that O'Neill had ten sons and four daughters who reached maturity.

His children include:

Owen Roe O'Neill ( – 6 November 1649); son of Art's wife O'Reilly Conn Ruadh O'Neill Brian MacArt O'Neill (died 1607); illegitimate son Niall O'Neill (died 1600) Art Oge O'Neill (died 1640); died at the siege of Barcelona. A daughter; married Miles O'Reilly A daughter; married into the Maguire family A daughter; married into the Magennis family A daughter; married into the O'Neill family of Upper Clandeboye