Chelsea lost last season's final to Barcelona in Gothenburg but Emma Hayes' side were seeded in pot one for Monday's draw having won the WSL.
In the competition's first-ever group stage, the Blues were drawn in Group A alongside Juventus, who have won the last four Serie A titles and are managed by former Arsenal head coach Joe Montemurro.
They will also come up against DFB Pokal holders Wolfsburg, having beaten the German side in the quarter-finals last season, and Swiss champions Servette - who overcame Glasgow City to reach this stage.
Despite the competition, Chelsea will still be favourites to progress as group winners, with the top two from each of the four groups qualifying for the quarter-finals.
Arsenal came through two qualifying rounds to reach the group stage having finished third in the WSL last season.
The Gunners will face holders Barcelona in Group C, where they were also paired with Hoffenheim and HB Koge.
Real Madrid, who eliminated Manchester City in the qualifiers, are in Group B along with Paris Saint-Germain, Breidablik and Kharkiv.
As well as a reformatted tournament, the Women's Champions League has a new television deal in place from the group stage onwards, with the matches streaming free on DAZN's YouTube channel.
Sparta Rotterdam 
AZ Alkmaar 
Southampton 
Liverpool 
Como 
Fiorentina 
Sevilla 
Rayo Vallecano 
Ajax 
Pec Zwolle 
Palermo 
Sampdoria 
Ipswich 
Manchester Utd 
Napoli 
Roma 
Moreirense 
FC Porto 
Leganes 
Real Madrid 
Lazio 
Bologna 
Empoli 
Udinese 
CSKA Moscow 
Rubin 
Slovan Bratislava 
AC Milan 
Sparta Praha 
Atletico Madrid 
Valencia 
Barcelona 
Stade Brestois 29 
Bayer Leverkusen 
Red Bull Salzburg 
Bayern Munich 
Paris Saint Germain 
Inter 
RB Leipzig 
Manchester City 
Feyenoord 
Sporting CP 
Arsenal 
FC Rostov 
Spartak Moscow 
Aston Villa 
Juventus 
Celtic 
Club Brugge 
Dinamo Zagreb 
Borussia Dortmund 
Monaco 
Benfica 
PSV 
Shakhtar Donetsk 
Lokomotiv Moscow 
Dinamo Moscow