Michael Keith

Character: Eric Carter

Harry Holcombe

Character: Dr. Arnold Johnson

James Yagi

Character: Yutaka Omura

Tadao Takashima

Character: Osamu Sakurai

Kenji Sahara

Character: Kazuo Fujita (as Keji Sahaka)

Ichirō Arishima

Character: Mr. Tako (as Ichiro Arishima)

George Takei

Character: Osamu Sakurai (voice) (uncredited)

Les Tremayne

Character: Mr. Tako / Dr. Shigesawa / Dr. Akira Makino / General Masami Shinzo / Commander Roberts / Narrator (voice) (uncredited)

Byron Morrow

Character: Newscaster (uncredited)

Mie Hama

Character: Fumiko Sakurai (uncredited)

Akiko Wakabayashi

Character: Tamiye (uncredited)

Akemi Negishi

Character: Chikiro's Mother (Dancing Girl) (uncredited)

Akihiko Hirata

Character: Dr. Shigezawa (uncredited)

Yū Fujiki

Character: Kinzaburo Furue (uncredited)

Jun Tazaki

Character: General Masami Shinzo (uncredited)

Yoshio Kosugi

Character: Faro Island Chief (uncredited)

Ikio Sawamura

Character: Witch Doctor (uncredited)

Kenzō Tabu

Character: Dreary Newscaster (uncredited)

Tatsuo Matsumura

Character: Dr. Akira Makino (uncredited)

Victor Millan

Character: Rodrigo Infanta (uncredited)

Douglas Fein

Character: Commander Roberts (uncredited)

Haruo Nakajima

Character: Godzilla (uncredited)

Shōichi Hirose

Character: King Kong (uncredited)

Katsumi Tezuka

Character: Godzilla in iceberg (uncredited)

Paul Mason

Character: Misc. Characters (voice) (uncredited)

Bruce Howard

Character: Misc. Characters (voice) (uncredited)