 | Javier Botet als Slender Man |
 | Joey King als Wren |
 | Julia Goldani Telles als Hallie |
 | Jaz Sinclair als Chloe |
 | Annalise Basso als Katie Jensen |
 | Kevin Chapman als M. Jensen |
 | Alex Fitzalan als Tom |
 | Miguel Nascimento als Kyle |
 | Michael Reilly Burke als Hallie's Dad |
 | Jessica Blank als Hallie's Mom |
 | Kayla Caulfield als High School Student |
 | Jeffrey Corazzini als Police Officer |
 | Michael Tow als Calculus Teacher |
| Adrian M. Mompoint als Jock |
| Danny Beaton als Burley Kid |
 | Taylor Richardson als Lizzie |
 | Kieran Tuomey als Student |
| Eddie Frateschi als Biology Teacher |
 | Oscar Wahlberg als Boy with Glasses |
 | Gabrielle Lorthe als Cheerleader |
| Marc Carver als Doctor |
 | Kris Sidberry als Librarian |
| Angela Hope Smith als Nurse |
| Timothy Brierley als Tour Guide |
| Damon D'Amico Jr. als Student |
| Yohanna Perez als Student |
| Sylvain White | Director |
| David Birke | Writer |
| Adam Kolbrenner | Executive Producer |
| Tracey Nyberg | Executive Producer |
| Javier Bennassar | Sound Designer |
| Andrea Ajemian | Co-Producer |
| Louis Sallerson | Executive Producer |
| William Sherak | Producer |
| Jake York | Editor |
| Nancy Nayor | Casting |
| Sarah Snow | Producer |
| Trevor Metz | Sound Effects Editor |
| Victor Surge | Characters |
| Brandon Campbell | Music |
| Deborah Newhall | Production Design |
| Robyn Meisinger | Producer |
| Ryan H. Cunningham | Executive Producer |
| James Vanderbilt | Producer |
| Brad Fischer | Producer |
| Kevin S. Parker | Sound Mixer |
| Blair Skinner | Production Supervisor |
| Luca Del Puppo | Director of Photography |
| Kim Leoleis | Set Decoration |
| Deborah Newhall | Costume Design |
| Mathieu Baptista | Special Effects Makeup Artist |
| Paula Dion | Hair Department Head |
| Julie LeShane | Special Effects Makeup Artist |
| Juliet Loveland | Makeup Department Head |
| JoJo Myers Proud | Key Makeup Artist |
| Shayna Passaretti | Key Hair Stylist |
| Shane Shisheboran | Special Effects Makeup Artist |
| Tom Davies | First Assistant Director |
| Jacki O'Brien | Second Assistant Director |
| Scooter Perrotta | Second Second Assistant Director |
| Megan Blake | Graphic Designer |
| Jesse Cambria | Greensman |
| Laura G. Foley | Property Master |
| Jonathan Gesinski | Storyboard Artist |
| Kimmie Johnson | Art Department Coordinator |
| Adam McClain | Construction Coordinator |
| Sean Andrew Murray | Concept Artist |
| Isaac Nadreau | Construction Foreman |
| Robert Schleinig | Leadman |
| Keith Thompson | Concept Artist |
| Anita Cannella | Foley Artist |
| Jeff Gross | Foley Mixer |
| Ryan Juggler | Sound Editor |
| Amy Kane | Foley Artist |
| Nick Offord | Sound Re-Recording Mixer |
| Jamey Scott | Sound Designer |
| Peter Stevenson | Boom Operator |
| Steven Ticknor | Sound Re-Recording Mixer |
| Steve Urban | Sound Editor |
| Ilyana Eberhardt | Stunt Double |
| Roy Farfel | Stunt Coordinator |
| Greg Harvey | Stunt Coordinator |
| John Vincent Mason | Utility Stunts |
| Nolan Ball | First Assistant "B" Camera |
| Thomas Bellotti | Second Assistant "B" Camera |
| Devon Catucci | Camera Operator |
| Terry Eden | Electrician |
| Felix Giuffrida | Second Assistant "A" Camera |
| Jesse Goldberg | Gaffer |
| Zachary K. Lazar | Genetator Operator |
| Scott Lebeda | Camera Operator |
| Roger Marbury | Rigging Gaffer |
| Dan Mason | First Assistant "A" Camera |
| Lucas McGowen | Aerial Camera |
| James R. Mitchell | Best Boy Electric |
| Melanie Patten | Lighting Technician |
| Steve Sikora | Lighting Technician |
| Dana Starbard | Still Photographer |
| Warren A. Weberg | Best Boy Grip |
| William M. Weberg | Key Grip |
| Heather Whitty | Extras Casting |
| Robin Chalfin | Tailor |
| Rosa J. Colón | Key Costumer |
| Debbie Holbrook | Costume Supervisor |
| Jennifer Lynn Tremblay | Assistant Costume Designer |
| Joshua Sgarlata | First Assistant Editor |
| Grant Conway | Music Editor |
| Nate Underkuffler | Music Editor |
| Aidan Payne | Script Supervisor |
| Tom Anas | Production Secretary |
| Erin Cole | Assistant Production Coordinator |
| Mary Fox | Production Accountant |
| Jill Sacco | Production Coordinator |
| Chetan Rathod | Visual Effects |
| Lance Ranzer | Visual Effects Supervisor |
| Ramin Djawadi | Original Music Composer |
