Regis Le Bris’ side will travel to Portugal to face SCU Torreense on October 15 before visiting Polish side Lech Poznan a week later.
GNK Dinamo will then arrive on Wearside on November 5, followed by Jagiellonia Białystok on November 26.
Sunderland will conclude their European fixtures in 2026 with a trip to Italy to face AC Milan on December 10.
The Black Cats begin 2027 away to RSC Anderlecht in Belgium before completing the league phase at home against PFC Levski Sofia on January 28.
Full Squad
Goalkeepers: Robin Roefs, Simon Moore.
Defenders: Omar Alderete, Dan Ballard, Kevin Danso, Trai Hume, Reinildo Mandava, Dayann Methalie, Thomas Meunier, Nordi Mukiele, Luke O’Nien.
Midfielders: Jules Ahoka, Habib Diarra, Enzo Le Fée, Chris Rigg, Noah Sadiki, Granit Xhaka.
Forwards: Nilson Angulo, Brian Brobbey, Malick Fofana, Wilson Isidor, Romaine Mundle.