Manchester United will face former striker Robin van Persie after being paired with Fenerbahce in the Europa League group stage.
The Red Devils will also face Feyenoord and Ukrainian outfit Zorya Luhansk in Group A.
United sold Van Persie to Turkish side Fenerbahce, who finished second in the Super Lig last season, in July 2015 after three years at Old Trafford.
Southampton, participating in the Europa League for the first time in their history, will take on Serie A giants Inter in Group K.
Claude Puel's charges have also been drawn against Sparta Prague and Hapoel Be'er Sheva, who were beaten by Celtic in the Champions League playoff round.
Irish outfit Dundalk have been handed a difficult group against Zenit, AZ Alkmaar and Maccabi Tel-Aviv in Group D.
Matchday one is on September 15 with the final games in the groups staged on December 8.
The full Europa League draw as follows:
Group A: Manchester United, Fenerbahce, Feyenoord, Zorya
Group B: Olympiacos, APOEL, Young Boys, Astana
Group C: Anderlecht, Saint-Etienne, Mainz, Qabala
Group D: Zenit, AZ Alkmaar, Maccabi Tel-Aviv, Dundalk
Group E: Viktoria Plzen, Roma, Austria Vienna, Astra
Group F: Athletic Bilbao, Genk, Rapid Vienna, Sassuolo
Group G: Ajax, Standard Liege, Celta Vigo, Panathinaikos
Group H: Shakhtar Donetsk, Braga, Gent, Konyaspor
Group I: Schalke, RB Salzburg, Kuban Krasnodar, Nice
Group J: Fiorentina, PAOK, Slovan Liberec, Qarabag
Group K: Inter, Sparta Prague, Southampton, Hapoel Be'er Sheva
