The 2021 AFC Cup qualifying play-offs were played from 7 April to 15 August 2021.
[1] A total of seven teams competed in the qualifying play-offs to decide three of the 38 places in the group stage of the 2021 AFC Cup.
Extra time and penalty shoot-out were used to decide the winner if necessary.
[1][3][4] The bracket of the qualifying play-offs for each zone was determined based on each team's association ranking, with the team from the higher-ranked association hosting the match.
The one winner of preliminary round 2 (from ASEAN Zone) and one winner of the play-off round (from South Zone) advanced to the group stage to join the 35 direct entrants.