Thirty-one county teams from the island of Ireland, plus London, compete.
This decision proved controversial - for instance, in the rescheduled Division 2 match between Louth and Meath which was played on 31 March 2018, Meath needed to win to avoid relegation while Louth had nothing to play for as they were already relegated irrespective of the result.
Eir Sport and TG4 provide live TV coverage of the league on Saturday nights and Sunday afternoons respectively.
The league concluded on 1 April 2018 with Dublin defeating Galway in the division 1 final.
The top two teams in Division 1 contest the National Football League final.