The draw was held on 27 August 2015, 17:45 CEST, at the Grimaldi Forum in Monaco. The 32 teams were drawn into eight groups of four, with the restriction that teams from the same association could not be drawn against each other. For the draw, the teams were seeded into four pots based on the following principles :
Pot 1 contained the title holders and the champions of the top seven associations based on their 2014 UEFA country coefficients. As the title holders were one of the champions of the top seven associations, the champions of the association ranked eighth were also seeded into Pot 1.
Pots 2, 3 and 4 contained the remaining teams, seeded based on their 2015 UEFA club coefficients.
Moreover, the draw was controlled for teams from the same association in order to split the teams evenly into the two sets of groups for maximum television coverage. The fixtures were decided after the draw. On each matchday, four groups play their matches on Tuesday, while the other four groups play their matches on Wednesday, with the two sets of groups alternating between each matchday. There are other restrictions: for example, teams from the same city in general do not play at home on the same matchday, and teams in certain countries do not play at home on the last matchday. 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. Therefore, Ukrainian clubs Shakhtar Donetsk and Dynamo Kyiv and Russian clubs Zenit Saint Petersburg and CSKA Moscow could not be drawn into the same group.
Teams
Below are the 32 teams which qualified for the group stage, grouped by their seeding pot. They include 22 teams which enter in this stage, and the 10 winners of the play-off round.
Key to colours
Group winners and runners-up advance to the round of 16
In each group, teams played against each other home-and-away in a round-robin format. The group winners and runners-up advanced to the round of 16, while the third-placed teams entered the Europa Leagueround of 32.
Tiebreakers
The teams are ranked according to points. If two or more teams are equal on points on completion of the group matches, the following criteria are applied in the order given to determine the rankings :
higher number of points obtained in the group matches played among the teams in question;
superior goal difference from the group matches played among the teams in question;
higher number of goals scored in the group matches played among the teams in question;
if, after having applied criteria 1 to 4, teams still have an equal ranking, criteria 1 to 4 are reapplied exclusively to the matches between the teams in question to determine their final rankings. If this procedure does not lead to a decision, criteria 6 to 12 apply;
superior goal difference in all group matches;
higher number of goals scored in all group matches;
higher number of away goals scored in all group matches;
higher number of wins in all group matches;
higher number of away wins in all group matches;
lower disciplinary points total based only on yellow and red cards received in all group matches ;
The matchdays are 15–16 September, 29–30 September, 20–21 October, 3–4 November, 24–25 November, and 8–9 December 2015. The match kickoff times are 20:45 CEST/CET, except for matchday 5 in Belarus and Russia and matchday 2 in Kazakhstan which are 18:00 CEST/CET, and matchdays 4 and 5 in Kazakhstan which are 16:00 CET. Times are CET/CEST, as listed by UEFA.
