The fixture list for the 2021 season was issued on 14 February 2021. The regular season comprised 18 rounds.[1]
The end-of-season play-offs featured the clubs finishing second to sixth in the regular season in a four round elimination competition to decide which team accompanied the team finishing first into the Championship for 2022.[2]
Four matches were postponed due under the RFL COVID-19 protocols and were not rearranged.[3]
All times are UK local time (UTC+1) on the relevant dates.
^Match original scheduled for 20 June but postponed on 18 June under RFL COVID-19 protocols due to a number of Keighley players either testing positive or being required to self-isolate.[12]
^Match postponed under COVID-19 protocols after Barrow reported seven or more players required to self-isolated through positive tests or close contacts.[21]
Workington Town, who finished the regular season in second place, advanced straight to the qualifying semi-final in the second week of the play-offs. Teams that finished 3rd to 6th after the regular season played off in qualifying and elimination play-offs respectively. Keighley Cougars defeated North Wales Crusaders in the qualifying play-off and proceeded to the qualifying play-off against Workington Town, where they lost.[29][30]Doncaster defeated Hunslet in the elimination play-off which resulted in the latter being eliminated from the play-offs.[31] Doncaster then proceeded to defeat North Wales in the elimination semi-final which saw them advance to the preliminary final against Keighley.[32]