The competition is named in honour of Matt Byrne (14 February 1870 – 21 September 1947), a former
Wicklow GAA club and county officer. By virtue of a quirk in translation, the Corn Uí Bhroin became known as the O'Byrne Cup even though Matt had never used an 'O' in his surname. Byrne was a native of
Baltinglass and taught at the local national school. Deeply involved in GAA activities at all levels throughout his life, he was regarded as a good footballer in his youth and an excellent
handballer. He was the first secretary of the
Maurice Davins' club in Baltinglass and served as a member of the Wicklow County Board for over 50 years, mostly as registrar. He represented Wicklow on
Leinster and
Central Councils and served as President of the
Irish Handball Council in 1941–44. Byrne died in 1947. The competition is contested by the eleven Leinster county teams (excluding
Kilkenny), although Third-level College teams have taken part occasionally. The competition is, together with the
Walsh Cup and
Kehoe Cup, part of a Leinster GAA Series which takes place each January. The most recent O'Byrne Cup winners were
Longford, who beat
Dublin in the 2024 final. The O'Byrne Shield was introduced in 2006 for teams knocked out at the first-round stage of the competition. It was later abandoned in 2013 due to the introduction of group stages in the competition, but re-introduced in 2024 when the O'Byrne Cup reverted to straight knockout format.{{cite web|url=https://www.independent.ie/sport/gaelic-games/gaelic-football/leinster-gaa-set-to-reformat-obyrne-cup-as-knockout-competition-for-2024/a954655098.html|title=Leinster GAA set to reformat O'Byrne Cup as knockout competition for 2024 ==Recent developments==