Champions Cup holders Saracens have been drawn against Toulon, Scarlets and Sale Sharks in next season's pool stages.
Sarries made history last month by becoming the first team to lift the trophy with a 100 per cent record, beating Racing 92 in the final. They were defeated by Toulon in the 2014 decider as the French powerhouse claimed the second of their three successive titles.
Munster and Leicester Tigers will meet for the second year in a row and the Irish province will also come up against their former fly-half Ronan O'Gara for the first time. They have been drawn in a difficult Pool 1 along with Top 14 champions Racing, for whom O'Gara is a coach, and Glasgow Warriors.
Pool 2 pits PRO12 winners Connacht against European heavyweights Wasps and Toulouse, and the inclusion of Italian minnows Zebre means two teams should qualify for the quarter-finals.
Exeter, Clermont Auvergne and Bordeaux-Begles have been drawn together for the second successive year in Pool 5 along with Ulster, while previous winners Leinster and Northampton are in with last season's Challenge Cup winners Montpellier and Castres.
In the Challenge Cup, West County rivals Bath and Bristol have been drawn in Pool 4 along with Cardiff Blues and Pau, who have World Cup winners Conrad Smith and Colin Slade and former England flanker Steffon Armitage in their ranks.
Three-time winners Harlequins will meet Edinburgh, Stade Francais and Romania's Timisoara Saracens in Pool 5, with 2015 champions Gloucester drawn against French duo La Rochelle and Bayonne and strugglers Benetton Treviso.
The Champions and Challenge Cup finals will be held at Murrayfield Stadium in Edinburgh on 12/13 May, 2017.
2016/17 European Rugby Champions Cup draw
Pool 1: Racing 92, Glasgow Warriors, Leicester Tigers, Munster
Pool 2: Connacht, Wasps, Toulouse, Zebre
Pool 3: Saracens, Toulon, Scarlets, Sale Sharks
Pool 4: Leinster, Montpellier, Northampton Saints, Castres
Pool 5: Exeter Chiefs, Clermont Auvergne, Ulster, Bordeaux-Begles
2016/17 European Rugby Challenge Cup draw
Pool 1: La Rochelle, Gloucester, Benetton Treviso, Bayonne
Pool 2: Ospreys, Grenoble, Newcastle Falcons, Lyon
Pool 3: Brive, Worcester Warriors, Newport Gwent Dragons, Enisei STM
Pool 4: Cardiff Blues, Bath, Pau, Bristol
Pool 5: Harlequins, Edinburgh, Stade Francais, Timisoara Saracens