The Italian took the decision in the wake of last night's 1-0 defeat to Austria, which all but ended Ireland's chances of qualifying for next year's World Cup in Brazil.
Rumours are already rife as to who will replace Trapattoni, although the FAI are said not to be in a major hurry to appoint a successor. Even so, Sports Mole has highlighted the five managers that are thought to be the early contenders for the role.
Having made 64 appearances for Northern Ireland during his playing career, O'Neill may not be high up on the list of some ROI supporters. Footballing rivalries aside, the 61-year-old could be just what the Greens need. He would provide some enthusiasm to the role, and could also freshen up the squad, which many believe is much needed. O'Neill is also known to be disappointed and a little hurt with how his last job, at Sunderland, ended. Consequently, he may feel that he has a point to prove.
There is a saying in football that encourages managers and players alike not to return to their former stomping grounds, so whether McCarthy would be tempted remains to be seen. It would be an emotional reunion for the current Ipswich Town boss, who guided Ireland to 2002 World Cup in South Korea and Japan, despite being drawn alongside both Holland and Portugal in qualification. They also gave a good account of themselves at the tournament, drawing with Germany before being knocked out by Spain on penalties in the second round.
It's a fairly safe bet that Keane would not form a management partnership with the man above him! The pair fell out at the aforementioned World Cup, as Keane was sent home for criticising Ireland's training base. Nevertheless, many regard the former Manchester United midfielder to be one of the best ever players to have pulled on a green shirt. While his management career - with Sunderland and Ipswich Town - may have been mixed, his experience as a player would earn him instant respect from the players.
He may have been sacked by Reading earlier this year, but McDermott is still highly regarded within the game. In fact, he had not been out of work for too long when Leeds United came calling for his services. He may not possess international experience, neither as a player nor manager, but he is often lauded for the style of football that his teams play. One of the main criticisms of Trapattoni was that he often sent out Ireland with a negative strategy.
Everything written about McDermott could also have been scribed for Norwich City's Hughton. He was harshly given his marching orders by Newcastle United in 2010, but he has since rebuilt his reputation with Birmingham City and has carried that on at Carrow Road. What is more, those that have voiced their disbelief at the fact that Wes Hoolahan was not given more of an opportunity in the Ireland starting lineup under Trapattoni, may be granted their wish with Hughton at the helm, given the Norwich connection.