Leicester City will face Napoli, Poland's Legia Warsaw and Spartak Moscow in the Europa League this season after being drawn in Group C on Friday.
Leicester's Premier League rivals West Ham United, who are making their group stage debut in the competition, have been handed trips to Croatia, Belgium and Austria after being drawn against Dinamo Zagreb, Genk and Rapid Vienna in Group H.
PSV Eindhoven, runners-up in the Dutch top-flight last season, have been placed in a tough Group B, which also includes AS Monaco, Spain's Real Sociedad and Austrian side Sturm Graz.
Scottish champions Rangers were drawn in Group A, where they will play France's Olympique Lyonnais, Czech side Sparta Prague and Danish club Brondby, while Celtic are in Group G alongside Bayer Leverkusen, Real Betis and Ferencvaros.
This season's competition involves 32 teams, down from 48 last season, but will have an extra knockout round before the last-16 stage.
European football's governing body Uefa has also scrapped the away goals rule, with the winners of each two-legged group tie to be decided by extra time and penalties if level on aggregate.
The Europa League final will be held at Seville's Ramon Sanchez Pizjuan stadium on May 18, with the group stages scheduled to start on September 16.
Europa League groups
Group A: Olympique Lyonnais, Rangers, Sparta Prague, Brondby
Group B: AS Monaco, PSV Eindhoven, Real Sociedad, Sturm Graz
Group C: Napoli, Leicester City, Spartak Moscow, Legia Warsaw
Group D: Olympiakos Piraeus, Eintracht Frankfurt, Fenerbahce, Royal Antwerp
Group E: Lazio, Lokomotiv Moscow, Olympique de Marseille, Galatasaray
Group F: Braga, Red Star Belgrade, Ludogorets, Midtjylland
Group G: Bayer Leverkusen, Celtic, Real Betis, Ferencvaros
Group H: Dinamo Zagreb, Genk, West Ham United, Rapid Vienna