- Jackson Beck
- King Luna / Moon People / Ghost Schoolmaster / Ghost Aircraft Leader / Walter Winchell / Mayor / Ghost 2 / Narrator / Little Boy / Clown (voice) (archive footage) (uncredited)
- Bradley Bolke
- Ghosts
- Gilbert Mack
- Mr. Galucci / Ghost (voice) (archive footage) (uncredited)
- Norma MacMillan
- Casper / Mrs. Smith (voice) (archive footage) (uncredited)
- Jack Mercer
- Moon People / Peacock / Monkeys / Spooky / Franz Schubert's Ghost / Ghosts / Octopus / Turtle / Kids / Joe / Mr. Flanigan / Salesman (voice) (archive footage) (uncredited)
- Mae Questel
- Wendy / Billy / Baby / Lucky / Little Ghosts' Teacher / Spooky / Kitten / Casper's Mom / Lou / Ladies at Door (voice) (archive footage) (uncredited)
- Sid Raymond
- Wheezy / Ghost 1 (voice) (archive footage) (uncredited)
- Cecil Roy
- Casper / Witch Hazel (voice) (archive footage) (uncredited)
- Alan Shay
- Casper
- Ed Sullivan
- Self
- Allen Swift
- Lookout
