Mysterious Doctor Satan

Eduardo Ciannelli

Doctor Satan

Robert Wilcox

Bob Wayne / Copperhead

William Newell

Speed Martin

C. Montague Shaw

Prof. Thomas Scott

Ella Neal

Lois Scott

Dorothy Herbert

Alice Brent

Charles Trowbridge

Gov. Bronson

Jack Mulhall

Police Chief Rand

Edwin Stanley

Col. Bevans

Walter McGrail

Stoner

Joe McGuinn

Gort

Bud Geary

Hallett

Paul Marion

Corbay

Archie Twitchell

Ross

Lynton Brent

Scarlett

Ken Terrell

Corwin

Al Taylor

Joe

George Allen

Henchman-Driver Spike (uncredited)

John Bagni

Gray, Pick-up Thug

Frank Brownlee

Panamint Pete