Giovanni Trapattoni's reign as Ireland manager is over after defeat in Austria effectively ended the nation's hopes of World Cup qualification.
Here, we take a look at some of the contenders for the vacancy.
Former Sunderland boss O'Neill is available after being shown the door at the Stadium of Light in March. The 61-year-old Northern Irishman has already been installed as the bookmakers' favourite, although it is understood he had not been contacted before Tuesday's 1-0 defeat at the Ernst Happel Stadion.
It was McCarthy who took Ireland to the 2002 World Cup finals in the Far East, where then skipper Roy Keane's differences with the Ireland set-up infamously came to a head. The current Ipswich boss had more than six years in charge of the country for which he played, and like O'Neill, the 54-year-old would enjoy popular support if he was appointed.
Hughton, 54, remains a hugely popular figure in Ireland, for whom he won 53 senior caps. An accomplished coach, he has established an enviable reputation as a manager after first stepping into the limelight at Newcastle, whom he guided back into the Barclays Premier League following relegation, and has impressed at both Birmingham and current club Norwich since.
For many, Keane would be the perfect man to shake things up with his no-holds-barred approach to the game. Currently working as a television pundit, the 42-year-old Cork man cut his teeth as a manager at Sunderland, winning promotion to the Premier League at the first attempt, and later guided Ipswich to the semi-finals of the Carling Cup.