The COVID-19 pandemic in Northern Ireland meant that the start of the season was delayed by approximately two months.
The 38-game season commenced on 16 October 2020 and concluded on 29 May 2021, with the European play-offs then taking place on 1 and 5 June 2021.
Linfield entered the 2021–22 UEFA Champions League first qualifying round, while runners-up Coleraine and 3rd-placed Glentoran joined the European play-off winners, Larne, in the 2021–22 UEFA Europa Conference League first qualifying round.
[2] The second and third tiers had not been granted 'elite' sporting status by the IFA which was required in order to continue playing matches during the COVID-19 pandemic lockdown.
Larne were the play-off winners, qualifying for European football for the first time in the club's history.