John Apicella as Frank (season 5)

Amy Aquino as Dr. Joan Avadon (season 4)

Beau Bridges as Nick Brody (season 5)

Max Burkholder as Jack McCallister (season 1, 2, 3)

Luc Charbonnier as Ben Tyler (season 3)

Richard Chamberlain as Jonathan Byrold (season 5)

Peter Coyote as Mark August (season 1)

Jeremy Davidson as Jack Randall (season 5)

Ryan Devlin as Seth Whitley (season 5)

Marika Dominczyk as Tyler Altamirano (season 1, 5)

Justine Dorsey as Sophie McCallister (season 1, 2, 3)

Edwina Findley as Jill (season 5)

Peter Gerety as Dennis York (season 4)

Danny Glover as Isaac Marshall (season 2)

Nigel Havers as Roger Grant (season 3, 4)

Josh Hopkins as Warren Salter (season 1)

Jay Karnes as Roy Scovell (season 4)

Matt Letscher as Alec Tyler (season 3, 4)

Jason Lewis as Chad Barry (season 1, 3)

Will McCormack as Ethan Tavis (season 3)

Denis O'Hare as Travis March (season 2, 4)

Ken Olin as David Caplan (season 2, 3, 4, 5)

Roxy Olin as Michelle McCormack (season 1, 4, 5)

Eric Christian Olsen as Kyle DeWitt (season 3)

Tyler Posey as Gabe Whedon (season 1)

Keri Lynn Pratt as Amber Trachtenberg (season 1)

Isabella Rae Thomas as Olivia (season 5)

Emily Rose as Lena Branigan (season 2)

Matthew Settle as Jonathan Sellers (season 1)

Tom Skerritt as William Walker (season 1, 2, 3, 4)

Sonja Sohn as Trish Evans (season 3)

Jon Tenney as Simon Craig (season 4)

John Terry as Karl West (season 5)

Steven Weber as Graham Finch (season 2, 3)

Treat Williams as David Morton (season 1)

Eric Winter as Jason McCallister (season 1, 2)

Odette Yustman as Annie Miller (season 5)