Owen Vaccaro (Lewis Barnavelt), Jack Black (Jonathan Barnavelt), Cate Blanchett (Florence Zimmerman), Kyle MacLachlan (Isaac Izard), Renée Elise Goldsberry (Selena Izard), Sunny Suljic (Tarby Corrigan), Vanessa Anne Williams (Rose Rita Pottinger) more..., Colleen Camp (Mrs. Hanchett), Lorenza Izzo (Mrs. Barnavelt), Eli Roth (Comrade Ivan), Braxton Bjerken (Woody Mingo), Ricky Muse (Bus Driver), Charles Green (Soda Jerk), De'Jon Watts (Clark), Aaron Beelner (Clown Automaton #1), Joshua Phillips (Clown Automaton #2), Christian Calloway (Azazel), Caleb Lawrence (Sweet Shop Employee), Dylan Gage Moore (Sweet Shop Boy), Jalyn Hall (Devin), Jackson T. Giles IV (Student), Alli Beckman (Magician's Assistant)

Eric Kripke (Screenplay), John Bellairs (Novel), Brad Fischer (Producer), Laeta Kalogridis (Executive Producer), Eric Kripke (Producer), W. Mark McNair (Executive Producer), Tracey Nyberg (Executive Producer) more..., William Sherak (Executive Producer), James Vanderbilt (Producer), Nicole Abellera (Casting), Jeanne McCarthy (Casting), Andres Cubillan (Art Direction), Walter P. Martishius (Art Direction), Ellen Brill (Set Decoration), Tommy Wilson (Set Decoration), Andrew S. Eisen (Editor), Fred Raskin (Editor), Rogier Stoffers (Director of Photography), Nathan Barr (Original Music Composer), Peter Staubli (Sound Designer), Jon Title (Sound Designer), Randy Torres (Sound Designer), Marlene Stewart (Costume Design),