The 2024 O'Byrne Cup, known for sponsorship reasons as the Dioralyte O'Byrne Cup, was a Gaelic football tournament played by eleven county teams of Leinster GAA in January 2024; Kilkenny did not take part. retained the trophy after beating in the final.
Teams defeated in their first match played in a shield tournament, which was won by .
The eleven teams are drawn to play in a knockout system, with six teams playing in a preliminary round and the other five receiving a bye to the quarter-finals.
The three losers in the preliminary round and two of the quarter-final losers are transferred to the O'Byrne Shield, which is also a straight knockout. This structure means that every team, except for , is guaranteed at least two games.