Michael Keith
Eric Carter

Harry Holcombe
Dr. Arnold Johnson

James Yagi
Yutaka Omura

Tadao Takashima
Osamu Sakurai

Kenji Sahara
Kazuo Fujita (as Keji Sahaka)

Ichirō Arishima
Mr. Tako (as Ichiro Arishima)

George Takei
Osamu Sakurai (voice) (uncredited)

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

Byron Morrow
Newscaster (uncredited)

Mie Hama
Fumiko Sakurai (uncredited)

Akiko Wakabayashi
Tamiye (uncredited)

Akemi Negishi
Chikiro's Mother (Dancing Girl) (uncredited)

Akihiko Hirata
Dr. Shigezawa (uncredited)

Yū Fujiki
Kinzaburo Furue (uncredited)

Jun Tazaki
General Masami Shinzo (uncredited)

Yoshio Kosugi
Faro Island Chief (uncredited)

Ikio Sawamura
Witch Doctor (uncredited)

Kenzō Tabu
Dreary Newscaster (uncredited)

Tatsuo Matsumura
Dr. Akira Makino (uncredited)

Victor Millan
Rodrigo Infanta (uncredited)

Haruo Nakajima
Godzilla (uncredited)

Shōichi Hirose
King Kong (uncredited)

Katsumi Tezuka
Godzilla in iceberg (uncredited)