Katsuhiko Sasaki
Inventor Goro Ibuki
Yutaka Hayashi
Hiroshi Jinkawa
Hiroyuki Kawase
Rokuro 'Roku-chan' Ibuki
K
Kanta Mori
Japan Special Defense Forces Chief
Kotaro Tomita
Lead Seatopian Agent
U
Ulf Otsuki
Seatopian Agent
S
Sakyo Mikami
Truck Driver's Assistant
F
Fumiyo Ikeda
Man from Unit 1
Robert Dunham
Emperor Antonio of Seatopia
G
Gentaro Nakajima
Truck Driver
R
Ralph Jesser
Antonio's Aide (Radio Operator in White)
S
Shinji Takagi
Godzilla
H
Hideto Odachi
Megalon
T
Tsugutoshi Komada
Jet Jaguar
M
Masachika Mori
Jet Jaguar
Kenpachirō Satsuma
Gigan
Gorō Naya
Emperor Atonio of Seatopia (voice)
E
Eisuke Nakanishi
Narrator
Haruo Nakajima
Godzilla (archive footage) (uncredited)
K
Kôetsu Ômiya
Anguirus
T
Teruo Nigaki
Rodan
E
Eisaburo Komatsu
E
Eisuke Nakanishi