Fitzgibbon first played for
Cork as a member of the
minor team during their unsuccessful
Munster MHC campaign in 2015. He immediately made the step up the
under-21 team, making his first appearance for the team in a seven-point defeat by
Limerick in June 2016. After another unsuccessful campaign the following year, Fitzgibbon won a
Munster U21HC medal in July 2018, in spite of leaving the field injured in Cork's 2-23 to 1-13 defeat of
Tipperary in the
final. Cork were later beaten by Tipperary in the
2018 All-Ireland U21HC final, in what was his last game in the grade. Fitzgibbon was later nominated for the Team of the Year. After being earlier added to the pre-season training panel, Fitzgibbon made his
senior team debut in a
National Hurling League defeat of
Clare in February 2017. His first
Munster SHC start came in a 2–27 to 1–26 win over Tipperary in May 2017. Fitzgibbon subsequently claimed his first provincial medal, after lining ot at midfield in Cork's 1-25 to 1-20 defeat of Clare in the
2017 Munster SHC final. He ended the season by receiving his first
All-Star nomination. Fitzgibbon won a second consecutive Munster SHC medal in July 2018, following a second consecutive 2-24 to 3-19 defeat of Clare in the
final. His performances throughout the season earned him his first All-Star award and a
Young Hurler of the Year nomination. Fitzgibbon lined out at midfield in Cork's 3-32 to 1-22 defeat by Limerick in the
2021 All-Ireland SHC final. He received further All-Star nominations in 2022 and 2023. Fitzgibbon lined out at midfield in Cork's 3-28 to 1-34 extra-time defeat by Clare in the
2024 All-Ireland SHC final. He ended the season by winning his second All-Star award, as well as being a
GAA/GPA Hurler of the Year nominee. Fitzgibbon claimed his first national silverware in April 2025 when Cork won the National Hurling League title following a 3–24 to 0–23 win over Tipperary in the final. Later that season, he won his third Munster SHC medal after a penalty shootout defeat of Limerick in the
2025 Munster SHC final. Fitzgibbon was again at midfield for the 3-27 to 1-18 defeat by Tipperary in the
2025 All-Ireland SHC final, in what was a second consecutive defeat in the final and a third defeat in five seasons. He ended the season, once again, by claiming a third All-Star award. Fitzgibbon succeeded
Robert Downey as
team captain in January 2026. ==Personal life==