The 2021 season was St Patrick's Athletic F.C.'s 92nd year in existence and is the Supersaint's 70th consecutive season in the top-flight of Irish football. It was the second full season with Stephen O'Donnell as manager, having taken over from Harry Kenny on 31 August 2019. Pre-season training for the squad began on 1 February 2021, the same day the league fixtures were announced, with the Saints revealed to be playing rivals Shamrock Rovers away in the opening game of the season on 19 March. The 2021 editions of the League of Ireland Cup and the Leinster Senior Cup were cancelled due to the delay in the start to the 2021 League of Ireland Premier Division as a result of the COVID-19 pandemic. The season was a hugely successful one for the club, as they secured a 2nd-place finish, securing UEFA Europa Conference League football for 2022, as well as winning the 2021 FAI Cup in front of an Aviva Stadium FAI Cup Final record crowd of 37,126.