The draw was carried out by ERC Chairman Jean-Pierre Lux and Chief Executive Derek McGrath, with the fourth Irish province, Connacht, plucked from tier 3.
Leinster, who ended the current season as Amlin Challenge Cup and RaboDirect PRO12 champions, were drawn in Pool 1 along with Northampton Saints, the Ospreys and Castres Olympique.
Facing Northampton will bring back members of Leinster's incredible 2011 Heineken Cup final victory over the Saints, while the Ospreys are regular opponents for the province in the PRO12 and Castres, the newly-crowned French champions, last met Leinster during the 2008/09 tournament.
Giving his reaction to the draw, Leinster captain Leo Cullen said: "We were massively disappointed not to get out of our pool last season. We came unstuck due to a number of factors but all the boys are mad keen to reach the knockout stages again - that is what it's all about for us.
"It's always funny at this time of year because it seems so far away. The finals were only a few weeks ago and obviously Northampton reached the Aviva Premiership final, which is no mean feat. I also watched Castres cause a bit of an upset by winning the Top 14.
"It's a tough pool all round - all the teams are pretty evenly matched. You always have to beat the best teams to win the Heineken Cup."
Leinster will have new head coach Matt O'Connor on board shortly, while Connacht's new boss Pat Lam is currently in his first week with the westerners and he will be licking his lips at the prospect of hosting Toulouse at the Sportsground.
Connacht have drawn French giants Toulouse for the second time in three seasons, and they will have league rivals Zebre as pool opposition for a second year running. Saracens, who were beaten semi-finalists this year, complete the Pool 3 line-up.
The westerners did the double on Zebre in the 2012/13 pool stages with a 25-20 win in Galway and a 19-10 success in Parma.
They went down both home and away to Toulouse during the 2011/12 campaign, losing 36-10 to Guy Noves' men in front of a 9,120-strong crowd at the Sportsground.
Ulster, meanwhile, have recent history with two of their opponents in Pool 5 - they won at home and lost away to English title holders Leicester Tigers in 2011/12 and are well used to tackling an ever-improving Benetton Treviso team.
Mark Anscombe's charges will also play French club Montpellier in the pool stages, hoping to make it four years on the trot that Ulster have reached the last-eight of the competition.
Munster, who lost to Clermont Auvergne in the semi-finals in April, head up Pool 6 with familiar foes Perpignan, Edinburgh and Gloucester completing the quartet.
The two-time European champions accouned for Edinburgh in the 2012/13 pool stages, including a 33-0 bonus point win at home, and will be hoping to build on Rob Penney's first season in charge.
The men in red enjoyed back-to-back pool victories over Perpignan in December 2009 (24-23 at home and 37-14 away), while the previous year saw them beat Gloucester 16-3 in an away quarter-final on the way to winning their last Heineken Cup crown.
2013/14 HEINEKEN CUP POOLS -
Racing Métro 92
2013/14 HEINEKEN CUP MATCHES DATES:
Round 1 - October, 11/12/13, 2013
Round 2 - October 18/19/20
Round 3 - December 6/7/8
Round 4 - December 13/14/15
Round 5 - January 10/11/12, 2014
Round 6 - January 17/18/19
Quarter-finals - April 4/5/6
Semi-finals - April 25/26/27
Final - May 23/24/25