Xabi Alonso's Real will play City at home and take on Premier League champions Liverpool at Anfield in what will be two of the standout fixtures of the league phase.
Arne Slot's Liverpool, who finished first in the league phase last season only to be eliminated by PSG in the last 16, will also play Atletico Madrid, PSV Eindhoven and Qarabag of Azerbaijan at home.
In addition, they must go to Inter Milan, Eintracht Frankfurt, Marseille and Turkish champions Galatasaray.
City, who won the Champions League in 2023, will welcome Borussia Dortmund, Bayer Leverkusen, Italian champions Napoli and Galatasaray to the Etihad Stadium.
As well as Real, they will also visit Villarreal, Monaco and Norwegian newcomers Bodo/Glimt.
PSG will entertain Bayern and go to Barcelona, while the French club also have home fixtures against Tottenham Hotspur and Newcastle United.
Luis Enrique's team went on to win the Champions League last season but only after struggling amid some difficult games in the league phase, in which they finished 15th.
They have no obviously straightforward fixtures this time, as they also face Atalanta at home, as well as Leverkusen, Sporting CP and Athletic Club away.
What is the Champions League format?
Every team now plays eight games against eight different opponents in the new format of Europe's elite club competition, which was introduced last season. All 36 clubs are pooled together into one league rather than split into groups.
The top eight teams advance to the last 16, while those finishing between ninth and 24th go into the knockout round play-offs. The bottom 12 teams are eliminated.
Other fixtures to look out for will include Barcelona visiting both Chelsea and Newcastle, while Arsenal entertain Bayern and Atletico and must also go to Inter Milan and to Bilbao.
Tournament newcomers Kairat Almaty of Kazakhstan, who ousted Celtic on penalties in the play-off round, will host Real and travel to London to play Arsenal. Minnows Pafos of Cyprus will visit Chelsea and face Bayern at home.
UEFA is not expected to announce specific fixture dates until Saturday, but the first round of games will take place across three days from September 16th to 18th. The eighth and final matchday is scheduled for January 28th.
This season's Champions League final will take place in the Hungarian capital, Budapest, on May 30th next year, with UEFA announcing on Thursday that the game will kick off at 18:00 local time rather than the usual 21:00.
Who qualified for the Champions League?
Below is the full list of 36 teams that qualified for the league phase, arranged in the Pots that were used in the draw:
Pot 1: PSG, Real Madrid, Manchester City, Bayern Munich, Liverpool, Inter Milan, Chelsea, Borussia Dortmund, Barcelona.
Pot 2: Arsenal, Bayer Leverkusen, Atletico Madrid, Benfica, Atalanta, Villarreal, Juventus, Eintracht Frankfurt, Club Brugge.
Pot 3: Tottenham Hotspur, PSV Eindhoven, Ajax, Napoli, Sporting CP, Olympiacos, Slavia Prague, Bodo/Glimt, Marseille.
Pot 4: FC Copenhagen, Monaco, Galatasaray, Royale Union Saint-Gilloise, Qarabag, Athletic Club, Newcastle, Pafos, Kairat Almaty.
If you want to know how the draw worked or about the competition, take a look at this article here, or check out the informative video from UEFA above.