The 2011–12 Heineken Cup was the 17th season of the Heineken Cup, the annual rugby union European club competition for clubs from the top six nations in European rugby.

[2][3] Leinster lifted the Heineken Cup by defeating fellow Pro12 and Irish side Ulster 42–14.

The victory gave Leinster their third Heineken Cup title in four years – a run of success unprecedented in the competition's history.

[9] The brackets show each team's European Rugby Club Ranking at the end of the 2010–11 season.

Under rules of the competition organiser, European Rugby Cup, tiebreakers within each pool are as follows.