Matthew Ramati (1 episode)
Dillon Macintosh
Nathan Blythe (13 episodes)
Dean Miller
McGrath
Governor Richard Jeffs
Mitch Bianci
Cal Jacobs (16 episodes)
Eric Dane (voice) (1 episode)
Doyle
Carter (4 episodes)
CO CDR Tom Chandler (56 episodes)
Casting (1 episode)
Marcus Gerber
Sean Jackson
Dr. Mark Sloan (2 episodes)
Sebastian Tunney
Self (2 episodes)
Self - Guest (2 episodes)
Self - Guest (1 episode)
Ben Grandy
James Madrox / Multiple Man
Mark Sloan (140 episodes)
Hero
Martin (6 episodes)
Leo Broder (2 episodes)
Charles "Tex" Watson
Jason Dean (9 episodes)
Overly Dramatic Actor
Rob Goodwin (3 episodes)
Dr. Wyatt Cooper (21 episodes)
Tom Emery
Mark Kelly (6 episodes)
Oliver Cole (1 episode)
Jimmy Warren (1 episode)
Tad Pogue (uncredited) (1 episode)