The 2021 Cork Senior A Football Championship was the second staging of the Cork Senior A Football Championship since its establishment by the Cork County Board. The draw for the group stage placings took place on 29 April 2021. The championship began on 3 September 2021 and ended on 28 November 2021.
The final was played on 28 November 2021 at Páirc UàChaoimh in Cork, between Mallow and St. Michael's, in what was their first meeting in a final in this grade. Mallow won the match by 2-12 to 0-15 to claim their first championship title.
Mark Buckley was the championship's top scorer with 1-24.
Promoted from the Cork Premier Intermediate Football Championship
Relegated from the Cork Premier Senior Football Championship
Promoted to the Cork Premier Senior Football Championship
Relegated to the Cork Premier Intermediate Football Championship