Michael Keith
Eric Carter
Harry Holcombe
Dr. Arnold Johnson
James Yagi
Yutaka Omura
Tadao Takashima
Osamu Sakurai
Kenji Sahara
Kazuo Fujita
Ichirô Arishima
Mr. Tako
Byron Morrow
Newscaster
Les Tremayne
Commander Roberts / General Masami Shinzo / Narrator (voice)
George Takei
Osamu Sakurai (voice)
Mie Hama
Fumiko Sakurai (uncredited)
Akiko Wakabayashi
Tamiye (uncredited)
Akemi Negishi
Chikiro's Mother (Dancing Girl) (uncredited)
Akihiko Hirata
Dr. Shigezawa (uncredited)
Bruce Mason
Misc. characters (voice)
Paul Howard
Misc. characters (voice)
Yû Fujiki
Kinsaburo Furue
Jun Tazaki
General Masami Shinzo (uncredited)
Yoshio Kosugi
Farou Island Chief (uncredited)
Ikio Sawamura
Witch Doctor (uncredited)
Kenzô Tabu
Dreary Newscaster (uncredited)
Victor Millan
Rodrigo Infante (uncredited)
Haruo Nakajima
Godzilla
Shōichi Hirose
King Kong