Yōsuke Natsuki as Detective Shindo

Yuriko Hoshi as Naoko Shindo

Hiroshi Koizumi as Professor Murai

Takashi Shimura as Dr. Tsukamoto

Emi Ito as Shobijin

Yumi Ito as Shobijin

Akiko Wakabayashi as Princess Maas Doulina Salno of Selgina

Hisaya Ito as Chief Assassin Malmess

Akihiko Hirata as Chief Detective Okita

Minoru Takada as Prime Minister

Someshō Matsumoto as Alien Expert

Ikio Sawamura as Honest Fisherman

Kōzō Nomura as Geologist

Kenji Sahara as Editor in Chief Kanamaki

Susumu Kurobe as Assassin with Mustache (uncredited)

Tōru Ibuki as Short-Tie Assassin

Kazuo Suzuki as Door-Opener Assassin

Haruya Katō as Journalist

Shin Ōtomo as Boss of Assassins

Senkichi Ōmura as Would-Be Hat Retriever

Yutaka Nakayama as Tourist with Lost Hat

Heihachirō Ōkawa as Astronomer

Hideyo Amamoto as Princess Salno's aide

Yoshio Kosugi as Chief of Infant Island

Yoshibumi Tajima as Ship Captain

Yutaka Oka as Meteoritic (uncredited)

Kôji Uno as Hotel Clerk (uncredited)

Shigeki Ishida as Man in Crowd (uncredited)

Toshihiko Furuta as Villager (uncredited)

Kotaro Tomita as Villager

Ichiya Aozora as Self / TV Host (uncredited)

Senya Aozora as Self / TV Host (uncredited)

Yuriko Hanabusa as Mother Shindo

Hideo Shibuya as Journalist

Haruo Nakajima as Godzilla

Shōichi Hirose as King Ghidorah

Masaki Shinohara as Rodan (uncredited)

Kōji Uruki as Rodan (uncredited)