The 1990–91 National Football League, known for sponsorship reasons as the Royal Liver Assurance National Football League, was the 60th staging of the National Football League (NFL), an annual Gaelic football tournament for the Gaelic Athletic Association county teams of Ireland.
Dublin defeated Kildare in the final.
Teams in all three divisions competed for the National Football League title.
Owing to the re-structure of the league, promotion and relegation did not take place in the same manner as it did under the same structure in other years.
In the event that teams finish on equal points, then a play-off will be used to determine group placings if necessary, i.e. where to decide relegation places or quarter-finalists.