Eduardo Ciannelli

as Doctor Satan

Robert Wilcox

as Bob Wayne / Copperhead

William Newell

as Speed Martin

C. Montague Shaw

as Prof. Thomas Scott

Ella Neal

as Lois Scott

Dorothy Herbert

as Alice Brent

Charles Trowbridge

as Gov. Bronson

Jack Mulhall

as Police Chief Rand

Edwin Stanley

as Col. Bevans

Walter McGrail

as Stoner

Joe McGuinn

as Gort

Bud Geary

as Hallett

Paul Marion

as Corbay

Archie Twitchell

as Ross

Lynton Brent

as Scarlett

Ken Terrell

as Corwin

Al Taylor

as Joe

George Allen

as Henchman-Driver Spike

John Bagni

as Gray, Pick-up Thug

Frank Brownlee

as Panamint Pete

James Bush

as Co-Pilot

Yakima Canutt

as Sailor at Winch

Virginia Carroll

as Nurse

Ed Cassidy

as Barton

Davison Clark

as Police Lieutenant

Tristram Coffin

as Wells - Governor's Secretary

Frank Conklin

as Station Master Burns

Fred Criswell

as Officer

Eddie Dew

as Gas Station Attendant

Frank Ellis

as Plant Henchman

James Fawcett

as Al

Sam Garrett

as Roper

Duke Green

as Duke - Mine Thug

Alan Gregg

as Red - Mine Thug

Kenneth Harlan

as Capt. Lathrop

Charles Hutchison

as Proprietor

Jerry Jerome

as House Heavy

Patrick Kelly

as Plant Henchman

Marten Lamont

as Steve - Pilot

Bert LeBaron

as Henchman Fallon

Jack O'Shea

as House Heavy

Eddie Parker

as Chuck - Lead Truck Thug

Hal Price

as P&G Warehouse Mgr.

Ernest Sarracino

as Henchman-Guard

Cy Schindell

as Jake - Biplane Pilot

William Stahl

as Detective Brock

Ted Stanhope

as Warehouse Watchman

Tom Steele

as Truck Henchman

Harry Strang

as Police Officer Davis

Duke Taylor

as Watkins - Fire Escape Thug

Robert Wayne

as Detective Perry

Wally West

as Palmer - Thug

Lloyd Whitlock

as Prof. Williams

Bill Wilkus

as Truck Henchman

Bud Wolfe

as Sailor at Cable