The former Shamrock Rovers boss has been linked with the upcoming vacancy at Celtic recently but O'Neill says his focus is fully on the tournament.
Meanwhile, Joe Ledley's Wales place at Euro 2016 is in serious doubt – after his club Crystal Palace confirmed the midfielder has suffered a fractured leg.
He now seems sure to miss the FA Cup final against Manchester United later this month.
Ledley was injured during Saturday's Premier League win over Stoke.
The Football Association of Wales says his condition will be assessed over the coming weeks.
