- Furankî Sakai
- Senichiro 'Sen-chan' Fukuda (AKA Bulldog)
- Hiroshi Koizumi
- Dr. Shin'ichi Chûjô
- Kyôko Kagawa
- Photographer Michi Hanamura
- Yumi Itô
- Shobijin (Twin Fairy)
- Emi Itô
- Shobijin (Twin Fairy)
- Jerry Itô
- Kurâruku Neruson
- Ken Uehara
- Dr. Harada
- Takashi Shimura
- News Editor
- Tetsu Nakamura
- Nelson's Henchman
- Seizaburô Kawazu
- General
- Yoshifumi Tajima
- Military Advisor
- Akihiko Hirata
- Doctor
- Kenji Sahara
- Helicopter Pilot
- Yoshio Kosugi
- Ship Captain
- Kôji Iwamoto
- Nelson's Henchman
- Kô Mishima
- Ship Survivor
- Toshio Miura
- Nelson's Henchman
- Akira Wakamatsu
- Nelson's Henchman
- Hiroshi Akitsu
- Nelson's Henchman / Survey Corps Member
- Hiroshi Takagi
- Nelson's Henchman
- Osman Yusuf
- Nelson's Rolisican Henchman
- Yasuhisa Tsutsumi
- Woodcutter
- Obel Wyatt
- Dr. Roff
- Harold Conway
- Rolisican Ambassador
- Teruko Mita
- Rest House Owner's Wife
- Robert Dunham
- Police Chief of New Kirk City
- Masamitsu Tayama
- Shinji Chûjô
- Ren Yamamoto
- Ship Survivor
- Haruya Katô
- Ship Survivor
- Rinsaku Ogata
- Ship Survivor
- Yutaka Nakayama
- Radio Communicator
- Kôji Uno
- Police Officer
- Wataru Ãmae
- Official
- Kazuo Hinata
- Defense Force Inspector / Audience Member (as Kazuo Higata)
- Mitsuo Matsumoto
- Police Officer
- Hiroyuki Satake
- Police Officer
- Shôichi Hirose
- Dam Worker
- Toshihiko Furuta
- Dam Worker
- Gorô Sakurai
- Member of Task Force
- Keisuke Matsuyama
- Shipmate
- Takeo Nagashima
- Island Dancer
- Kôji Kamimura
- Small Role
- Akira Yamada
- Island Worshipper
- Mitsuo Tsuda
- Captain Orion Maru / Surveyor
- Akio Kusama
- Surveyor
- Tadashi Okabe
- Doctor Hayakaze / Surveyor
- Hideo Shibuya
- Journalist
- Shigeo Katô
- Dam Watchman
- Kazuo Imai
- Announcer
- Yutaka Oka
- Captain of Transport
- Kô Hayami
- Island Dancer
- Yoshio Katsube
- Investigation Party Member
- Haruo Nakajima
- Head of Mosura Larva
- Katsumi Tezuka
- Neck of Mosura Larva
- Ryôji Shimizu
- Investigation Party Member
- Yôichirô Kitagawa
- (as Ryûichi Hosokawa)
- Junnosuke Suda
- (scenes deleted)
- Yû Sekita
- (as Hiroshi Sekita)
- Akira Kitchôji
- (scenes deleted)
- Masaaki Tachibana
- Newspaper Reporter
- Toshiko Nakano
- (scenes deleted)
- Tsurue Ichimanji
- (scenes deleted)
- Nanako Yamada
- Native Girl
- Enver Altenbay
- Airplane passenger
- Ryûtarô Amami
- Nitto Shimbun Reporter
- Shizuko Azuma
- National Nuclear Research Center Staff
- Kenzô Echigo
- Helicopter Pilot
- Kohei Furukawa
- Geiger
- Bin Furuya
- Reporter
- Yukihiko Gondô
- Dam Staff
- Cliff Harrington
- Rolisican citizen
- Shinjirô Hirota
- Dam Staff
- Hans Horneff
- New Kirk City citizen
- Saburô Iketani
- Show Announcer
- Minoru Itô
- Defense Force Member counting down
- Sabel Jameel
- New Kirk City citizen
- Saburô Kadowaki
- National Nuclear Research Center Staff
- Kuniyoshi Kashima
- Survey Team Member
- Nobuo Katsura
- Show Audience Member
- Masayoshi Kawabe
- Police Officer Search Team Member
- Ikuo Kawamura
- Ship Association Staff / show spectator / Self-Defense Forces Member (uncredited)
- Ed Keane
- New Kirk City Government Official
- Yoshie Kihira
- Nitto Shimbun's Waitperson / Show Audience Member (uncredited)
- Eisaburo Komatsu
- Ship Association Staff / Self-Defense Forces Member (uncredited)
- Jun Kuroki
- Dam Staff
- Ed P. MacDamott
- New Kirk City citizen
- Jirô Mitsuaki
- Nitto Shimbun Reporter
- Sachiko Môri
- Nurse of National Nuclear Research Center
- Takashi Narita
- Infant Island Islander / Show Audience Member / Defense Corps Executive (uncredited)
- Masaya Nihei
- Dam Policeman / Infant Island Islander (uncredited)
- Terumi Oka
- Theater Receptionist
- Matsue Ono
- National Nuclear Research Center Staff
- Animatronic Puppet
- Mothra
- Enrico Rossi
- Father of New Kirk City
- Keiji Sakakida
- National Nuclear Research Center Staff
- Haruya Sakamoto
- Airport Cop
- Kôichi Satô
- Defense Corps Executive
- Akira Sera
- Infant Islander
- Masaki Shinohara
- National Nuclear Research Center Staff
- Shigemi Sunagawa
- Nitto Shimbun Reporter
- Jirô Suzukawa
- Infant Islander
- Haruo Suzuki
- Self - Defense Forces Member
- Kamayuki Tsubono
- Defense Force Officer / Airport Police Officer (uncredited)
- Akihide Tsuzawa
- Island Boy
- Shirô Watanabe
- Nitto Shimbun Reporter
- Takuya Yuki
- National Nuclear Research Center Staff / Announcer (uncredited)
- Tokio Ãkawa
- Infant Island Citizen / Survey Team Member (uncredited)
- Hideo Ãtsuka
- Police Officer Search Team Member
