The 2021 season was originally scheduled to begin on 11 March 2021, however, on 14 January 2021, it was announced that all clubs had agreed to push the start date back by two weeks, to increase the chances of fans being able to attend matches.

[1] St Helens were the reigning champions going into Super League XXVI, after successfully retaining their title against Wigan Warriors, in the Grand Final.

Super League XXVI also saw the return of the Magic Weekend, which took place at St James' Park in Newcastle, after it was cancelled in 2020 due to the COVID-19 pandemic.

[4] St Helens won their 3rd Grand Final in a row, (9th title overall), after narrowly beating Catalans Dragons 12-10 at Old Trafford on 9 October 2021.

[5] Secondly, a set of protocols were introduced, allowing for matches to be postponed, if a team had seven or more players from the senior squad unavailable, due to either close contact or a positive COVID-19 test.

Dual registration will not be allowed, but loans will be, with the minimum load period reduced to fourteen days.

[7] Super League Europe announced in February 2021 that the matches in round 2 would be played to support retired player Mose Masoe in his rehabilitation from a serious back injury suffered during a game in 2020.

With only fourteen senior players available due to injury and COVID-19 precautions Castleford could not raise a team and forfeited the game.

[23] Huddersfield became the second Super League team to forfeit a game in 2021 when the round 13 match against Castleford was cancelled on 4 July.

The top 2 teams who finished first and second respectively in the regular season table (Catalans Dragons and St Helens respectively, had byes to the semi-finals.

The four teams who finish third to sixth contested in two elimination finals, with the winner of those two games moving on to the semi-finals (Hull Kingston Rovers and Leeds Rhinos respectively).