Leinster will begin next season's Heineken Champions Cup campaign away to reigning champions La Rochelle.
The repeat of last year's final takes place on Sunday, December 10th.
Connacht are the first Irish side into action on Friday December 8th, with a home match against Bordeaux.
Ulster are away to Bath on the Saturday, with Munster at home to Bayonne.
Full fixtures (all kick-offs Irish time)
Connacht v Bordeaux-Begles, Friday 8 December, 8pm (The Sportsground)
Bath v Ulster, Saturday 9 December, 3.15pm (The Rec)
Munster v Bayonne, Saturday 9 December, 5.30pm (Thomond Park)
La Rochelle v Leinster, Sunday 10 December, 3.15pm (Stade Marcel Deflandre)
Saracens v Connacht, Saturday 16 December, 1pm (StoneX Stadium)
Leinster v Sale Sharks, Saturday 16 December, 5.30pm (RDS/Aviva Stadium)
Ulster v Racing 92, Saturday 16 December, 8pm (Kingspan Stadium)
Exeter Chiefs v Munster, Sunday 17 December, 1pm (Sandy Park)
Lyon v Connacht, Saturday 13 January, 1pm (Stadium de Gerland)
Toulon v Munster, Saturday 13 January, 3.15pm (Stade Felix Mayol)
Leinster v Stade Francais, Saturday 13 January, 5.30pm (RDS/Aviva Stadium)
Ulster v Toulouse, Saturday 13 January, 8pm (Kingspan Stadium)
Connacht v Bristol Bears, Friday 19 January, 8pm, (The Sportsground)
Harlequins v Ulster, Saturday 20 January, 1pm (The Stoop)
Leicester Tigers v Leinster, Saturday 20 January (Welford Road)
Munster v Northampton Saints, Saturday 20 January (Thomond Park)