| 1999 O'Byrne Cup | |
| Province: | Leinster |
| Year: | 1999 |
| Matches: | 9 |
| Date: | 10 January — 6 March |
| Num Teams: | 10 |
| Trophy: | O'Byrne Cup |
| Winners: | Dublin |
| Manager: | Tommy Carr |
| Captain: | Dessie Farrell |
| Runnersup: | Louth |
| Runnerupcaptain: | Martin Farrelly |
| Runnerupmanager: | Paddy Clarke |
| Ordinal: | 5 |
| Previous: | 1998 |
| Next: | 2000 |
The 1999 O'Byrne Cup was a Gaelic football competition played by the county teams of Leinster GAA.
The tournament was a straight knockout, with 10 teams. Kildare (who took a team holiday instead[1]) and Kilkenny did not compete.
Dublin were the winners, defeating Louth in the final in Parnell Park, a victory overshadowed by the death of one of the umpires, John Buckley, shortly after the game.[2] [3]