Celtic were drawn in Group H where they will meet the Italian giants, as well as Lille and Sparta Prague.
Mikel Arteta’s Arsenal, beaten finalists in 2019, will play Rapid Vienna, Molde and Dundalk in Group B.
Dundalk defeated KI Klaksvík 3-1 in Dublin on Thursday to reach the group stages for just the second time in their history, with Shamrock Rovers the only other Irish side to make it that far in 2011.
Tottenham face trips to Bulgaria, Austria and Belgium to play Ludogorets, LASK and Royal Antwerp.
Having come up against Porto in the group stages last season, Steven Gerrard’s Rangers side will again travel to Portugal to face Benfica, as well as Standard Liege and Lech Poznan.
Leicester also meet Portuguese opposition after being drawn in Group G alongside Braga, AEK Athens and Ukranian side Zorya Luhansk.
Before the draw, Inter Milan striker Romelu Lukaku was named UEFA Europa League player of the season 2019/20 after scoring seven goals in the tournament last season.
Europa League draw in full:
Group A: Roma, Young Boys, Cluj, CSKA Sofia
Group B: Arsenal, Rapid Vienna, Molde, Dundalk
Group C: Bayer Leverkusen, Slavia Prague, Hapoel Be’er-Sheva, Nice
Group D: Benfica, Standard Liege, Rangers, Lech Poznan
Group E: PSV Eindhoven, PAOK, Granada, Omonia
Group F: Napoli, Real Sociedad, AZ Alkmaar, NK Rijeka
Group G: Braga, Leicester, AEK Athens, Zorya Luhansk
Group H: Celtic, Sparta Prague, AC Milan, Lille
Group I: Villareal, Qarabag, Maccabi Tel-Aviv, Sivasspor
Group J: Tottenham, Ludogorets, LASK, Royal Antwerp
Group K: CSKA Moscow, Dinamo Zagreb, Feyenoord, Wolfsberg
Group L: Gent, Red Star Belgrade, Hoffenheim, Slovan Liberec
When does the football start?
The group stages get underway in the week of October 19, with six rounds of group games running through to mid-December.
- Matchday 1: October 22
- Matchday 2: October 29
- Matchday 3: November 5
- Matchday 4: November 26
- Matchday 5: December 3
- Matchday 6: December 10
Whoever is lucky enough to go all the way will go head to head at the Stadion Energa Gdansk in Poland on May 26 next year. Seville, the prospective 2021 host, will now host the 2022 event.
Any other business?
Video Assistant Referee (VAR) will not be introduced for the group phase, as was the original plan. It will still be used in the knockout stage, with introduction for the group stage in 2021/22.
When are the other draws?
- Round of 32 draw: December 14
- Round of 16 draw: February 26
- Quarter-final and semi-final draws: March 19