 | Jessica Chastain als Annabel |
 | Nikolaj Coster-Waldau als Lucas Desange |
 | Megan Charpentier als Victoria Desange |
 | Isabelle Nélisse als Lilly Desange |
 | Daniel Kash als Dr. Dreyfuss |
 | Melina Matthews als Mama (voice) |
 | Morgan McGarry als Young Victoria |
 | Javier Botet als Mama (body) |
 | Jane Moffat als Jean Podolski / Mama (Voice) |
 | David Fox als Burnsie |
 | Dominic Cuzzocrea als Ron |
 | Julia Chantrey als Nina |
 | Ray Kahnert als Judge |
 | Christopher Marren als Cop |
 | Matthew Edison als Young Cop |
 | Diane Gordon als Louise |
| Bárbara Muschietti | Producer |
| Luis Sequeira | Costume Design |
| Fernando Velázquez | Original Music Composer |
| Anastasia Masaro | Production Design |
| Guillermo del Toro | Executive Producer |
| J. Miles Dale | Producer |
| Michele Conroy | Editor |
| Andy Muschietti | Director |
| Robin D. Cook | Casting |
| Jeffrey Cassidy | Video Assist Operator |
| Antonio Riestra | Director of Photography |
| Javier Aller | Production Assistant |
| Elis Y. Lam | Art Direction |
| Patricia Cuccia | Set Decoration |
| Kari Measham | Set Decoration Buyer |
| Andrij Molodecky | Set Dresser |
| John 'Butch' Rose | Set Dresser |
| Greg Chapman | Sound Re-Recording Mixer |
| Alfredo Díaz | Sound Effects Editor |
| Allan Fung | Supervising Sound Editor |
| Gabriel Gutiérrez | Sound Designer |
| Marc Orts | Sound Re-Recording Mixer |
| Suzanne Aplin | Costume Supervisor |
| Andy Muschietti | Story |
| Andy Muschietti | Screenplay |
| Bárbara Muschietti | Story |
| Bárbara Muschietti | Screenplay |
| Neil Cross | Screenplay |
| Alison Reid | Stunts |
| Doug Reid | Best Boy Electric |
| Dana Howes | Transportation Coordinator |
