Detective Brian McGregor (1 episode)
Gen. Jeffrey Amherst
Calvin Weber (1 episode)
Coach Allen
Sam Barnes
Bob Orlinger
XO Mike Slattery (56 episodes)
Metamorpho / Rex Mason (voice) (3 episodes)
Steven Harris (3 episodes)
Colonel Michael Vance (2 episodes)
Wilson (voice)
Ethan Slaughter (2 episodes)
Parasite (voice) (1 episode)
Dr. Graham Barrett
Breakdown (voice) (11 episodes)
Mr. Clements
DHS Agent Brett Dunbar (1 episode)
Carl Herrod
Disgruntled Bodyguard
John Casey (91 episodes)
Superman / Clark Kent / Dark Superman (voice)
Jesse Carter
Lenny
Chad Shelten (13 episodes)
Special Agent Jamie Kenton (1 episode)
Mike Rogo
Jayne Cobb
Special Agent Danny Love (13 episodes)
Jeff Stenn
Michael Rainer (1 episode)
Marcus Hamilton (5 episodes)
Colonel Dave Dixon (2 episodes)
Cmdr. Michael Rainer (1 episode)
Dr. Viades
Jay Forrest
Det. Mark Winston
John Gacy, Sr.
De Soto (1 episode)
Lance Bishop
Jayne Cobb (11 episodes)
Chris Myers / Keyman
Christopher Bannon
Vinnie Krailes
Mel James
Peter Clerkin
Knowle Rohrer (5 episodes)
Chad Harmon
York (voice) (2 episodes)
Agent X (voice) (13 episodes)
Finn (voice) (41 episodes)
Old West Finn (voice) (1 episode)
Finn / E.B. MacDonald (voice) (1 episode)
Finn / Ulf (voice) (1 episode)
Finn / Coach (voice) (1 episode)
Finn / Carnival Worker (voice) (1 episode)
Gameshow Host (voice) (1 episode)
Captain Wagner
Dr Jekyll / Mr Hyde
Capt. Wilkins
Jimmy, the bartender
Major James Bowen (1 episode)
Jeremy Butler
Jack Ellway
Fred Haise (1 episode)
Michael O'Ryan (4 episodes)
Michael O'Ryan / Joe York (1 episode)
Col. Jack Riles (22 episodes)
John Reed
Major Mitchell
Ralph Fiske (1 episode)
Finn's Father
Captain West
Burt Miller
Thomas Hughes
Scott Cooper (1 episode)
Sgt. Hastings
Tom McLaury
Tommy Wright
Mark Tullis Jr.
Mitch
Alec Danz
Officer Black
Det. John Taylor (2 episodes)
The King
Stoney Ptak
FBI Agent #1
Garber
Joey Rosselin
Carter
Animal Mother
Skip Jackson
Jeff Hannah
Ike Dimick
Mickey South
Randy Daniels
Albert Hockenberry
Bobo McKenzie
Stillman
Ricky Linderman