The Cup holders were Premier Division side Shamrock Rovers and they again reached the final where they were defeated 4-2 by Dundalk after extra-time.
[2] The winners of the FAI Cup earns automatic qualification for the 2021–22 UEFA Europa Conference League and would begin play in the first qualifying round.
If they have already qualified for European competition through position in the 2020 Premier Division, the spot will go to league's fourth place finisher Sligo Rovers.
The draw for the quarter-finals took place on 18 September 2020 after the league game of Sligo Rovers vs. Bohemians live on RTÉ2.
Former Sligo Rovers FAI Cup winning captain Conor O'Grady drew the games.