The 2021 Copa Libertadores group stage was played from 20 April to 27 May 2021.
[2] The draw for the group stage was held on 9 April 2021, 12:00 PYT (UTC−4), at the CONMEBOL Convention Centre in Luque, Paraguay.
Teams from the same association could not be drawn into the same group, excluding the four winners of the third stage, which were seeded in Pot 4 and whose identity was not known at the time of the draw, and could be drawn into the same group with another team from the same association.
[2] The winners and runners-up of each group advanced to the round of 16 of the final stages.
The third-placed teams of each group entered the round of 16 of the 2021 Copa Sudamericana.