[4] His father, Dessie played hurling as a goalkeeper for All Saints, Antrim GAA, and Ulster whilst his brother Sean, was a track athlete who competed from Northern Ireland in the Men's 800 metres at the 1982 Commonwealth Games.

[5][6] Raised Catholic,[7] he briefly attended Presentation Convent Primary School before the family moved to Ballymena, County Antrim.

[4] He also played association football at youth level for Ballymena's Star United FC for four years before joining Chimney Corner as a 14-year-old.

O'Neill agreed to join Austrian club Sturm Graz on a Bosman free transfer in 1996 but changed his mind after an offer to return to English football with Coventry City where he spent just over two years.

[10] After spending time on loan to Aberdeen and Reading during the 1997–98 season O'Neill left Coventry to sign for Wigan Athletic in September 1998.

[21] O'Neill led Rovers to the 2011 Setanta Sports Cup and then made history by being the first manager of a League of Ireland team to reach the group stages of a European competition.

[32] During their 2014 FIFA World Cup qualification, Northern Ireland earned some creditable results, including a 1–1 draw away to Portugal and a 1–0 home win against Russia.

[33] In November 2013, O'Neill agreed a new two-year deal with Irish Football Association to remain as Northern Ireland manager.

At the tournament itself he led the side to the second round, losing narrowly to Wales[36] but recorded a surprise victory over Ukraine in the group stages.

[47] Stoke's preparations for the season restart were disrupted after O'Neill tested positive for coronavirus on 9 June which caused a training match against Manchester United to be cancelled.

O'Neill brought in a number of free transfers including James Chester, Morgan Fox, Steven Fletcher and Mikel John Obi with Jacob Brown the only arrival to have been bought.

[50] Stoke began the season well with Tyrese Campbell in decent form, winning eight of their first 16 matches and were just outside the play-off places at the beginning of December.

[51] However a number of injuries to key players most notably to Tyrese Campbell saw goals dry up and the team went nine games without a win at the turn of the year.

[54] This enabled O'Neill to add to his squad with the arrivals of Jack Bonham, Romaine Sawyers, Sam Surridge, Mario Vrančić and Ben Wilmot.

[59] In October 2023, after a section of protestant unionist Northern Irish association football fans protested news that, if they qualify, Northern Ireland would play their home Euro 2028 fixtures at a redeveloped Casement Park, the home of Antrim GAA in a predominately Catholic and nationalist part of Belfast, O'Neill said "I would like to see it supported.

[60] O'Neill himself is a Roman Catholic and played gaelic football at youth level for county Antrim in the original Casement Park.