The 2020–21 UEFA Europa League knockout phase began on 18 February with the round of 32 and ended on 26 May 2021 with the final at Stadion Miejski in Gdańsk, Poland, to decide the champions of the 2020–21 UEFA Europa League.
The team that scored more goals on aggregate over the two legs advanced to the next round.
If the aggregate score was level, the away goals rule was applied, i.e. the team that scored more goals away from home over the two legs advanced.
If no goals were scored during extra time, the winners were decided by a penalty shoot-out.
In the final, which was played as a single match, if the score was level at the end of normal time, extra time was played, followed by a penalty shoot-out if the score was still level.
[2] The mechanism of the draws for each round was as follows: On 17 July 2014, the UEFA emergency panel ruled that Ukrainian and Russian clubs would not be drawn against each other "until further notice" due to the political unrest between the countries.
[4] In the knockout phase, teams from the same or nearby cities (Arsenal and Tottenham Hotspur) were not scheduled to play at home on the same day, due to logistics and crowd control.
To avoid such scheduling conflicts, UEFA had to make adjustments.
For the round of 32, since both teams were seeded and play the second leg at home, the home match of the team that was not domestic cup champions in the qualifying season, or the team with the lower domestic ranking (if neither team were the domestic cup champions, i.e. Tottenham Hotspur for this season), was moved from Thursday to Wednesday.
[5] For the round of 16, quarter-finals, and semi-finals, if the two teams were drawn to play at home for the same leg, the order of legs of the tie involving the team with the lowest priority was reversed from the original draw.
[6] The schedule was as follows (all draws were held at the UEFA headquarters in Nyon, Switzerland).