Holders Bordeaux-Begles will face former winners Munster in next season's Champions Cup rugby pool stage, after the draw was made on Wednesday.
The French club will also play the Stormers as well as Bristol and Gloucester in Pool 3, with fellow Top 14 outfit Racing 92 also in the group but they will not face each other as they are from the same domestic league.
One hurdle for the 2025 and 2026 winners could be a tough trip to South Africa, with exact fixture locations to be announced in due course.
Last season's runners up Leinster are in Pool 1 alongside Pau, Sale, Leicester, Clermont and fellow United Rugby Championship side Glasgow.
Record six-time champions Toulouse will play winners on three occasions Saracens and English Prem runners up Exeter in Pool 3.
English Prem champions Northampton will meet Montpellier, who lifted the second-tier Challenge Cup in May and lost in last weekend's Top 14 final, in Pool 4.
Next season's competitions will also introduce three major changes including the teams qualifying for the last 16.
The three highest ranked clubs from each pool will still reach the knock-outs with the remaining four places going to teams with the highest points across the group, regardless of their pool.
Additionally, an attacking bonus point will now be awarded if a team scores three tries or more than their opponents as opposed to just four times in an attempt to avoid lopsided scorelines.
The opening round of games has been moved forward to the weekend of October 16-18 from mid-December to build attention around the competitions before the Nations Championship test match window in November.
The final takes place on May 22 in Lyon, with the Challenge Cup's decider taking place 24 hours earlier in French city.
Champions Cup draw
Pool 1: Leinster (IRL), Glasgow (SCO), Pau (FRA), Sale (ENG), Leicester (ENG), Clermont (FRA)
Pool 2: Toulouse (FRA), Lions (RSA), Saracens (ENG), La Rochelle (FRA), Exeter (ENG), Connacht (IRL)
Pool 3: Bordeaux-Begles (FRA), Stormers (RSA), Racing 92 (FRA), Munster (IRL), Bristol (ENG), Gloucester (ENG)
Pool 4: Northampton (ENG), Bath (ENG), Cardiff (WAL), Montpellier (FRA), Stade Francais (FRA), Bulls (RSA)
Challenge Cup draw
Pool 1: Cheetahs (RSA), Ulster (IRL), Perpignan (FRA), Dragons (WAL), Bayonne (FRA), Zebre (ITA)
Pool 2: Treviso (ITA), Lyon (FRA), Newcastle (ENG), Sharks (RSA), Castres (FRA), Scarlets (WAL)
Pool 3: Ospreys (WAL), Edinburgh (SCO), Black Lion (GEO), Harlequins (ENG), Toulon (FRA), Vannes (FRA)