Gammera the Invincible

Albert Dekker

Secretary of Defense

Brian Donlevy

Gen. Terry Arnold

Diane Findlay

Sgt. Susan Embers

John Baragrey

Capt. Lovell

Dick O'Neill

Gen. O'Neill

Mort Marshall

Jules Manning

Alan Oppenheimer

Dr. Contrare

Steve Zacharias

Sen. Billings

Thomas Stubblefield

J.T. Standish

Gene Bua

Lt. Clark

Bob Carraway

Lt. Simpson

John McCurry

A1C Hopkins

Walter Arnold

American Ambassador

Louis Zorich

Soviet ambassador

Robin Craven

British ambassador

Bernard Grant

Dr. Hidaka (voice)

Larry Robinson

Aoyagi (voice)

Paulette Rubinstein

Kyoke (voice)

Lucy Martin

Nobuyo (voice)

Corinne Orr

Toshio (voice)

Peter Fernandez

Professor Murase / Captain Foster / New York newsreader / Mr. Ueda (voices)

Kenneth Harvey

Chidori Maru navigator (voice)

Jack Curtis

news announcer (voice)

William Griffis

misc. roles (voice)