Toulon will start their bid for a fourth consecutive European title at home to Bath when the Champions Cup gets under way in mid-November.
The champions, who beat Clermont Auvergne to win the title in May, will host Bath in Pool Five on 14 November.
Premiership winners Saracens start their campaign the same day at home to four-time champions Toulouse.
Pro12 winners Glasgow Warriors travel to Racing 92 while Wasps take on Leinster and Ospreys host Exeter.
The competition kicks off on Friday, 13 November when Leicester Tigers host French Top 14 champions Stade Francais.
Oyonnax will play their first game in Europe's top competition at home to Ulster at the Stade Charles Mathon.
Gloucester open against Zebre, Northampton welcome Scarlets to Franklin's Gardens and Wasps travel to Dublin to face Leinster.
The final will take place at Lyon's new Grand Stade de Lyon, which is due to open later this year, on 14 May 2016.
|Champions Cup round one fixtures|
|Friday, 13 November||Leicester v Stade Francais||Pool 4|
|Saturday, 14 November||Oyonnax v Ulster||Pool 1|
|Racing 92 v Glasgow Warriors||Pool 3|
|Saracens v Toulouse||Pool 1|
|Munster v Benetton Treviso||Pool 4|
|Northampton v Scarlets||Pool 3|
|Sunday, 15 November||Leinster v Wasps||Pool 5|
|Bordeaux-Begles v Clermont||Pool 2|
|Toulon v Bath||Pool 5|
|Ospreys v Exeter Chiefs||Pool 1|
|Full list of fixtures|