Paris Saint-Germain and Manchester City, two of the leading candidates to win the Champions League, will face each other in the group stage of this season's competition after coming out together in Thursday's draw.
Pep Guardiola's City beat PSG in the semi-finals of last season's Champions League on the way to losing the final to Chelsea in Porto.
The Portuguese forward is being strongly linked with a move to Abu Dhabi-owned City from Juventus before the European transfer window closes on Tuesday, August 31.
Holders Chelsea will play Juventus in Group H and both clubs will be expected to advance from a section also including Russian champions Zenit Saint Petersburg and Malmo.
Saint Petersburg will host this season's Champions League final on May 28 next year.
Thursday's draw in Istanbul also saw Barcelona come out in a fascinating Group E along with Bayern, Benfica and Ukrainian champions Dynamo Kiev.
Liverpool will face Spanish champions Atletico Madrid, meaning a return to the Wanda Metropolitano stadium where they beat Tottenham Hostpur in the 2019 final to win the European Cup for the sixth time.
Manchester United came out in Group F with Villarreal, Atalanta and Swiss champions Young Boys.
Real Madrid, the record 13-time European champions, are in the same group as Italian champions Inter Milan and Shakhtar Donetsk of Ukraine for the second straight season.
The first round of fixtures will be played on September 14 and 15.