Update 2.55pm: Champions Leinster have been drawn in Pool 1 for the 2018/19 Champions Cup.
They will begin their title defence against English sides Wasps and Bath and four-time champions Toulouse.
Meanwhile, Munster were drawn in Pool 2 where they will face English Premiership runners-up Exeter Chiefs.
Joining them are Casters and Gloucester.
Elsewhere in Pool 4, Ulster will face Scarlets, Racing 92 and Leicester Tigers.
Update 2.40pm: Paddy Jackson will be making a sooner-than-expected return to Irish shores.
His new side Perpignan have been drawn in the same European Challenge Cup pool as Connacht.
Joining them in a tough Pool 3 will be Sale Sharks and Bordeaux-Begles.
Earlier: Munster, Leinster and Ulster to learn of Champions Cup pool opponentsThe pool draws for the Champions Cup and the Challenge Cup take place today with all four Irish provinces to learn of their opponents.
European champions Leinster join Munster and Ulster in the Champions Cup draw while Connacht will play in the Challenge Cup this season.
You can watch the pool draws live below:
In the Champions Cup draw, there are four tiers to decide the five pools.
Tier 1: Castres Olympique (TOP 14 winners), Saracens (Premiership winners) Leinster Rugby (PRO14 winners) and two of Montpellier, Exeter Chiefs and Scarlets.
Tier 2: Racing 92, Wasps, Glasgow Warriors, one of Montpellier, Exeter Chiefs and Scarlets as well as the fourth-ranked club from the same league as the one not drawn into Tier 1.
Tier 3: Toulouse, Leicester Tigers, Edinburgh Rugby and the two remaining fourth-ranked clubs.
Tier 4: RC Toulon, Bath Rugby, Cardiff Blues, Ulster Rugby, Gloucester Rugby
As announced by the EPCR, the following rules will apply for the draw:
"Each pool will have at least one club from each of the three leagues and each of the five pools will have one club from each of the four tiers.
"There will be no more than two clubs from the same league in a pool and no pool will contain two PRO14 clubs from the same country.
"Clubs from the same league will be kept apart until the allocation of the Tier 4 clubs."