Jacob Tremblay Orion (voice) Paul Walter Hauser Dark (voice) Angela Bassett Sweet Dreams (voice) Colin Hanks Adult Orion (voice) Natasia Demetriou Sleep (voice) Golda Rosheuvel Unexplained Noises (voice) Nat Faxon Insomnia (voice) Aparna Nancherla Quiet (voice) Ike Barinholtz Light (voice) Carla Gugino Orion's Mom (voice) Matt Dellapina Orion's Dad (voice) Shannon Chan-Kent Adult Hypatia (voice) Jack Fisher Richi Panichi (voice) Werner Herzog Narrator (voice) Sky Alexis Lisa (voice) Hira Ambrosino Woman at the Drive-In (voice) Yoshi Ando Man at the Drive-In (voice) Sean Charmatz Irene's Boss / Cucumber Dentist / Soda / Insomnia Guy 1 (voice) Walt Dohrn Stray Cat / Insomnia Guy 2 (voice) Ren Hanami Adult Sally (voice) Amy Hill Irene (voice) Toru Uchikado Insomnia Man (voice)