Jay Ryan (Ben Hanscom), Angelica Alejandro (Asian Waitress), Andy Bean (Stanley Uris), Stephen Bogaert (Mr. Marsh), Ari Cohen (Rabbi Uris), John Connon (John Koontz), Kate Corbett (Dean's Mom), Jack Dylan Grazer (Young Eddie), Lyla Elliott (Dead Young Girl), Taylor Frey (Don Hagarty), Teach Grant (Henry Bowers), Nicholas Hamilton (Young Henry), Chosen Jacobs (Young Mike), Chris Jiggins (Paramedic), Erik Junnola (Bully), Elena Khan (Derry towns people), Ryan Kiera Armstrong (Victoria), Sophia Lillis (Young Beverly), Divan Meyer (Audience Member), Wyatt Oleff (Young Stanley), Janet Porter (Richie's Mother), Rob Ramsay (Meaner Nurse), Jeremy Ray Taylor (Young Ben), Jackson Robert Scott (Georgie Denborough (rumored)), Jake Sim (Belch Huggins), Connor Smith (Carny), Noah-Anthony Smith (Civilian), Owen Teague (Patrick Hockstetter), Logan Thompson (Victor Criss), Angela Thompson (Comedy Show Patron), Anthony Ulc (Joe The Butcher), Kelly Van der Burg (Victoria's Mom), Shannon Widdis (Cheerleader #1), Finn Wolfhard (Young Richie)

Stephen King, Gary Dauberman

Camille Kennedy, Sylvain Arseneault, Rob Beal, Kris Fenske, Brian Horrell, Daryl Purdy, Robert Woolfson

Seth Grahame-Smith, David Katzenberg, Roy Lee, Dan Lin, Barbara Muschietti, Marty P. Ewing, John Powers Middleton

KatzSmith Productions, Lin Pictures, New Line Cinema, Vertigo Entertainment