| Jason Schwartzman | | Jesper (voice) |
| J.K. Simmons | | Klaus (voice) |
| Rashida Jones | | Alva (voice) |
| Will Sasso | | Mr. Ellingboe (voice) |
| Neda Margrethe Labba | | Márgu (voice) |
| Sergio Pablos | | Pumpkin / Olaf (voice) |
| Norm MacDonald | | Mogens (voice) |
| Joan Cusack | | Mrs. Krum (voice) |
| Evan Agos | | Ellingboe Boy (voice) |
| Sky Alexis | | Ellingboe Girl 2 (voice) |
| Jaeden Bettencourt | | Krum Boy / Jesper's Son (voice) |
| Teddy Blum | | Small Ellingboe Boy (voice) |
| Mila Brener | | Ellingboe Girl 3 (voice) |
| Sydney Brower | | Ellingboe Girl (voice) |
| Finn Carr | | Ellingboe Boy 1 (voice) |
| Kendall Joy Hall | | Annelise (voice) |
| Hailey Hermida | | Krum Girl 1 (voice) |
| Lexie Holland | | Additional Kids Voices (voice) |
| Brooke Huckeba | | Additional Kids Voices (voice) |
| Matthew McCann | | Additional Kids Voices (voice) |
| Tucker Meek | | Ellingboe Boy / Krum Boy (voice) |
| Leo Miller | | Ellinboe Boy 5 (voice) |
| Joaquin Obradors | | Additional Kids Voices (voice) |
| Víctor Pablos | | Additional Kids Voices (voice) |
| Lucian Perez | | Krum Boy / Creepy Boy 2 (voice) |
| Bailey Rae Fenderson | | Creepy Girl 2 (voice) |
| Maximus Riegel | | Additional Kids Voices (voice) |
| Emma Shannon | | Creepy Girl 1 (voice) |
| Ayden Soria | | Creepy Boy 1 (voice) |
| Sunday Sturz | | Additional Kids Voices (voice) |
| Hudson West | | Additional Kids Voices (voice) |
| Gordon Wilcox | | Additional Kids Voices (voice) |
| Emma Yarovinsky | | Little Krum Girl (voice) |
| Julian Zane Chowdhury | | Krum Boy (voice) |
| Brad Abrell | | Additional Adults Voices (voice) |
| Cathy Cavadini | | Additional Adults Voices (voice) |
| Bill Chott | | Additional Adults Voices (voice) |
| Daniel Crook | | Additional Adults Voices (voice) |
| Brian T. Finney | | Additional Adults Voices (voice) |
| Stephen Hughes | | Additional Adults Voices (voice) |