The 2012–13 Heineken Cup was the 18th season of the Heineken Cup, the annual rugby union European club competition for clubs from the top six nations in European rugby.

The tournament began with two pool matches on 12 October 2012 and ended with the final at the Aviva Stadium in Dublin on 18 May 2013.

In the cases of England and France, this does not necessarily match the teams' placement in their national leagues in the preceding season.

[13] The brackets show each team's European Rugby Club Ranking at the end of the 2011–12 season.

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