Last season's Heineken Cup runners-up Ulster will be in Pool 4 alongside Northampton Saints, Glasgow Warriors and Castres Olympique, while two-time winners Munster are up against Edinburgh, Saracens and Racing Metro 92 in Pool 1.
Current English Premiership champions Harlequins are in Pool 3 with Biarritz Olympique, their regular European rivals Connacht and Italian newcomers Zebre.
In tandem with the draw, ERC also announced that the Amlin Challenge Cup final, which gets the Dublin 2013 finals weekend underway, will kick off at 8pm at the RDS on Friday, May 17.
2012/13 HEINEKEN CUP POOL DRAW:
POOL 1: MUNSTER, Edinburgh Rugby, Saracens, Racing Metro 92
POOL 2: Toulouse, Leicester Tigers, Ospreys, Benetton Treviso
POOL 3: Biarritz Olympique, Harlequins, CONNACHT, Zebre
POOL 4: Northampton Saints, ULSTER, Glasgow Warriors, Castres Olympique
POOL 5: LEINSTER, Clermont Auvergne, Scarlets, Exeter Chiefs
POOL 6: Cardiff Blues, Toulon, Sale Sharks, Montpellier
Round 1 - October 12/13/14, 2012
Round 2 - October 19/20/21, 2012
Round 3 - December 7/8/9, 2012
Round 4 - December 14/15/16, 2012
Round 5 - January 11/12/13, 2013
Round 6 - January 18/19/20, 2013
Quarter-finals - April 5/6/7, 2013
Semi-finals - April 26/27/28, 2013
Dublin 2013 Finals -
Amlin Challenge Cup final - RDS, Friday, May 17, 2013 (8pm)
Heineken Cup final - Aviva Stadium, Saturday, May 18, 2013 (5pm)