The 2021 Joe McDonagh Cup was the fourth staging of the Joe McDonagh Cup since its establishment by the Gaelic Athletic Association in 2018. The competition, which was delayed for a second successive year due to the impact of the COVID-19 pandemic on Gaelic games, began on 26 June 2021. The fixtures were published on 21 April 2021.
Antrim, winner of the 2020 final, were promoted to the Leinster Senior Hurling Championship, while there was no relegation to or from the competition. Down and Kildare entered the competition from the Christy Ring Cup.
On 17 July 2021, Westmeath won the Joe McDonagh Cup after a 2âÂÂ28 to 1âÂÂ24 win over Kerry in the final at Croke Park. It was their first ever cup title having previously lost two finals.
Meath's Jack Regan was the championship's top scorer with 1-36.
Relegated from the All-Ireland Senior Hurling Championship
Promoted from the Christy Ring Cup
Promoted to the All-Ireland Senior Hurling Championship
Relegated to the Christy Ring Cup
Westmeath are promoted to the 2022 All-Ireland Senior Hurling Championship.
Kildare are relegated to the 2022 Christy Ring Cup.