Akira Takarada

Lt. Commander Jiro Nomura

Mie Hama

Madame Piranha

Rhodes Reason

Commander Carl Nelson

Linda Miller

Lieutenant Susan Watson

Hideyo Amamoto

Dr. Who

Yoshibumi Tajima

Henchman

Sachio Sakai

Henchman

Ryuji Kita

SDF General

Ikio Sawamura

Native

Nadao Kirino

Henchman

Shōichi Hirose

Henchman

Kazuo Suzuki

Henchman

Tōru Ibuki

Henchman

Naoya Kusakawa

Susumu Kurobe

Henchman

Haruo Nakajima

King Kong

Hiroshi Sekita

Mechani-Kong/Gorosaurus

Kei Taguchi

(voice)

Akiko Santo

(voice)

Osman Yusuf

Submariner (uncredited)

Tadashi Okabe

Soldier (uncredited)

Seishirō Kuno

Soldier (uncredited)

Yasuhisa Tsutsumi

General (uncredited)

Andrew Hughes

Reporter (uncredited)