Cantwell first played hurling and Gaelic football to a high standard as a student at Killina Presentation Secondary School.
He was part of the club's senior football team that beat Tubber in 2018 to win the Offaly SBFC title.
[3] Cantwell first appeared on the inter-county scene for Offaly during an unsuccessful one-year tenure with the under-20 team in 2020.
[4] He was later drafted onto the senior team and made his debut in a National Hurling League defeat of Wicklow in 2021.
[5] Cantwell won a Joe McDonagh Cup medal as an unused substitute in 2024 after a defeat of Laois in the final.