Saracens will begin their quest for a third successive European Champions Cup crown with a trip to Aviva Premiership rivals Northampton.
Saints will host the back-to-back champions at Franklin's Gardens on Sunday, Oct. 15 at the end of a busy opening weekend.
The 2017-18 Champions Cup season kicks off on Friday, Oct. 13 as Wasps travel to Belfast to take on Ulster.
Standout fixtures on the Saturday include Leicester's trip to Paris to face Racing 92, while Premiership champions Exeter host Glasgow.
PRO12 winners Scarlets face an opening weekend trip to Toulon on Oct. 15 before compatriots Ospreys host Clermont.
In the Challenge Cup, holders Stade Francais face the daunting trip to Russia on the opening weekend to face Krasny Yar.
Beaten finalists Gloucester are also away, as they kick off this season's competition at Pau on Thursday, Oct. 12.
London Irish begin life back in Europe, following their year in the Championship, with a home tie against Edinburgh.