Clark

Professor Cleary (2 episodes)

Christopher Parsons (1 episode)

Werner

Derek Longbrake (6 episodes)

George Venturi

Dr. Modan

Whit Randolph (2 episodes)

Mr. Chandler (1 episode)

MCRN Admiral (1 episode)

William Rathcart

FDA Chairman

Tom O'Neill

Joel Coleman (1 episode)

Greg Dale

Gregor

Paul (2 episodes)

MacGregor

Stevens

Detective Jakobsson

Stuart Wells

Reuben

Tom Miller

Richard

Walter "Walt" Jackson

John Buckhout

Donald Adams (1 episode)

Burt

Lucy's Father

Bill

Sasha Antonov (10 episodes)

Walter (2 episodes)

Mr. Miles Hollingsworth II

George

Associate Producer

Robert Bryce (3 episodes)

Detective Mike

Andrew Pederson

Thomas Novak (1 episode)

John Wexford

Mr. Miles Hollingsworth II (2 episodes)

Mitch Deerfoot (1 episode)

Danny McClure (10 episodes)

Dr. Joseph Mars (1 episode)

George Venturi

William Rivers (1 episode)

(23 episodes)

Matt Hawkins

Dr. William Shaw

Ming the Merciless (21 episodes)

Oskar

Lucius (26 episodes)

Quentin Baxter

(1 episode)

Dr. Garth Bender

Jack Avenir

Len Taft (1 episode)

(1 episode)

George Venturi (70 episodes)

(1 episode)

Paul Keaton

Jason Sloan

Richard Carroll

Carl (1 episode)

Steve 42

(1 episode)

Frank Sinatra

Elliott

Mr. Borquin

Mulcahy's Date

David Delaney

Dr. Raymond Fuchs / Stephen (1 episode)

Mr. White

D.A. Barry Fenley

Jack Berg (32 episodes)

Riley Del Deegan (1 episode)

Airport Gunman

(1 episode)