Brian O'Neill, Baron Dungannon

Brian Ó Néill, Baron Dungannon (died 18 April 1562) was an Irish aristocrat of the Elizabethan era. He was part of the O'Neill dynasty, a powerful Gaelic family in Ulster. Brian's father was Matthew O'Neill, 1st Baron Dungannon who had been given his title by Henry VIII as part of the surrender and regrant policy. Matthew was assassinated by his half-brother and rival Shane O'Neill in 1558. Shane tried to have the government recognise Matthew and his sons as illegitimate, but they continued to be supported by the Viceroy the Earl of Sussex in Dublin.

In 1562 Shane and Brian were ordered to attend the Court in London to present their cases to Elizabeth I and her ministers. Shane came to London, but while Brian was travelling from Newry to Carlingford he was assassinated by Turlough Luineach O'Neill, almost certainly on the orders of Shane.[1] While Shane made a melodramatic submission to the Queen in London, she only partly accepted his claims. Despite being acknowledged as the most powerful Ó Néill, he was not made an Earl as he had wished. Shane was himself assassinated five years later by the MacDonnells of Antrim.

Brian was succeeded by his younger brother Hugh who eventually became Earl of Tyrone and head of the Ó Néills. His other brothers were Cormac and Arthur.[2] In Gaelic form he is often known as Brian mac Baron Ó Néill.