 Taissa FarmigaSister Irene | Sister Irene |
 Anna PopplewellKate | Kate |
 Jonas BloquetMaurice Theriault | Maurice Theriault |
 Storm ReidSister Debra | Sister Debra |
 Katelyn Rose DowneySophie | Sophie |
 Léontine d'OncieuSimone | Simone |
 Anouk Darwin HomewoodCéleste | Céleste |
 Sarah PachoudEmily | Emily |
 Suzanne BertishMadame Laurent | Madame Laurent |
 Bonnie AaronsThe Demon Nun / Valak | The Demon Nun / Valak |
 Peter HudsonFather Ridley | Father Ridley |
 Tamar BaruchSister Amara | Sister Amara |
 Natalia SafranSister Chloe | Sister Chloe |
 Maxime Elias-MenetJacques | Jacques |
 Pascal AubertFather Noiret | Father Noiret |
 Alexandra GentilSister Astrid | Sister Astrid |
 Florence MestaisDouble Demon Nun | Double Demon Nun |
| MMargaux BorelDouble Demon Nun | Double Demon Nun |
| VViviana MoinSister Maria | Sister Maria |
| RRenata PalminielloSister Pia | Sister Pia |
| FFulvia Patrizia OlivieriAbbess | Abbess |
| CCamille AmielJulie | Julie |
| MMargot MorrisAurélie | Aurélie |
 Gaël RaësCedric the Altar Boy | Cedric the Altar Boy |
| LLieve CarchonSister Concetta | Sister Concetta |
 David HorovitchCardinal Conroy | Cardinal Conroy |
 Paul SperaDeacon Scott | Deacon Scott |
 Kate ColebrookIrene's Mother / St. Lucy | Irene's Mother / St. Lucy |
 Margot BernazziYoung Irene | Young Irene |
 Grégory Di MeglioHotel Clerk | Hotel Clerk |
