Thirty-two Gaelic football county teams from the island of Ireland, plus London, participated.
On 29 April, Cork defeated Mayo by 2-10 to 0-11 to win their eight league title and their third in a row.
[1] The 2012 format of the National Football League was a system of four divisions.
Compete in Division 1 semi-finals Automatic relegation to Division 2 1Dublin are placed ahead of Donegal because they won the head-to-head game between the teams (2-16 to 0-13).
2Meath are placed ahead of Monaghan because they won the head-to-head game between the teams (1-15 to 1-09).