Pep Guardiola will return to former club Barcelona with Manchester City in the Champions League after the two sides were thrown together in Thursday's group stage draw in Monaco.
Guardiola, a European Cup winner with Barca as a player in 1992 before twice guiding the Catalan giants to the Champions League title in 2009 and 2011, will also come up against Borussia Moenchengladbach and Celtic in Group C.
Defending champions Real Madrid, who won a record 11th European Cup last season, were paired with Borussia Dortmund in Group F alongside Portugal's Sporting and Legia Warsaw of Poland.
Five-time winners Bayern Munich will play last year's beaten finalists Atletico Madrid in Group D, which also features PSV Eindhoven and Russian competition debutants Rostov.
Paris Saint-Germain and Arsenal are the two clear favourites to progress from Group A ahead of Basel and Bulgarian outfit Ludogorets, while Premier League champions Leicester City were handed a favourable draw in Group G which includes Porto, Club Brugge and FC Copenhagen.
Juventus will take on three-time reigning European League champions Sevilla as well as Lyon and Dinamo Zagreb in Group H.
The first matches will be played on September 13 and 14.