The 2018–19 European Rugby Champions Cup pool stage is the first stage of the 24th season of European club rugby union, and the fifth under the European Rugby Champions Cup format.

For the purpose of creating the tiers, clubs are ranked based on their domestic league performances and on their qualification for the knockout phases of their championships.

[2] Teams in the same pool play each other twice, at home and away, in the group stage that begins on the weekend of 12/13/14 October 2018, and continues through to 18/19/20 January 2019.

The five pool winners and three best runners-up progress to the quarter-finals.

Teams are awarded group points based on match performances.