Leinster will open their bid for an historic three Heineken Cup titles in a row with a home match against tournament newcomers, Exeter Chiefs, at the RDS, Dublin on 13 October.
The 2012 champions, who also triumphed in 2009 and 2011, will then travel to Llanelli to play the Scarlets the following Saturday before facing ASM Clermont Auvergne in back-to-back ties in December with the Round 4 clash set to take place in the Aviva Stadium.
Last season's beaten finalists Ulster will get their campaign underway at home to Castres Olympique on 12 October.
Mark Anscombe's men will follow that up with a trip the new Scotstoun Stadium where they face Glasgow. They will face a exciting double header against Northampton Saints in December.
Munster will beging their campaign away to Racing Metro 92 at the French national stadium, Stade de France on 13 October.
A week later Munster will take on last year's Heineken Cup semi-finalists Edinburgh, before they take on Saracens in back to back December fixtures.
Connacht, meanwhile, have been handed a dream start as they take on Italian newcomers Zebre in Parma on October 13.
The following week will see Harlequins travel to the Sportsground, the venue where their Heineken Cup hopes were crushed in dramatic fashion last season.
There are back to back matches against Biarritz in December with the French side visiting the Sportsground for the first time on Friday 7 December.