The 2018 Copa Libertadores group stage was played from 27 February to 24 May 2018. A total of 32 teams competed in the group stage to decide the 16 places in the final stages of the 2018 Copa Libertadores.
<section begin=Draw /><noinclude> The draw for the group stage was held on 20 December 2017, 20:00 PYST (), at the CONMEBOL Convention Centre in Luque, Paraguay.
Teams were seeded by their CONMEBOL ranking of the Copa Libertadores (shown in parentheses), taking into account of the following three factors:
</noinclude> For the group stage, the 32 teams were drawn into eight groups (Groups AâÂÂH, also denoted as Groups 1âÂÂ8) of four containing a team from each of the four pots. Teams from the same association could not be drawn into the same group, excluding the winners of the third stage, which were allocated to 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.
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The following were the four winners of the third stage of qualifying which joined the 28 direct entrants in the group stage.
<section begin=Format /> In the group stage, each group was played on a home-and-away round-robin basis. The teams were ranked according to points (3 points for a win, 1 point for a draw, and 0 points for a loss). If tied on points, the following criteria were used to determine the ranking: 1. Goal difference; 2. Goals scored; 3. Away goals scored; 4. CONMEBOL ranking (Regulations Article 28).
The winners and runners-up of each group advanced to the round of 16 of the knockout stages. The third-placed teams of each group entered the Copa Sudamericana second stage.<section end=Format />
The fixture list was determined by the draw as follows:
The matches were played on 27âÂÂ28 February, 1, 13âÂÂ15 March, 3âÂÂ5, 11, 17âÂÂ19, 24âÂÂ26 April, 1âÂÂ3, 15âÂÂ17 and 22âÂÂ24 May 2018.