The pair have signed on for multi-episode guest arcs on the FX series, and both will be playing showbiz types in Los Angeles, the new stomping grounds for plastic surgeons Sean McNamara (Dylan Walsh) and Christian Troy (Julian McMahon).
Platt is set to appear in five episodes as a TV producer named Freddy Prune, according to The Hollywood Reporter. The two doctors will serve as consultants on a show Prune produces. Hutton, meanwhile, will play a publicist whose star client has some work done at McNamara/Troy.
Hutton will guest in at least three episodes, in her first acting job in several years. Her movie and TV credits include "54," "Central Park West," "Paper Dolls" and "American Gigolo."
Platt earned a pair of Emmy nominations for his work on Showtime's "Huff" in 2005 and '06; he was also nominated in 2001 for guest work on "The West Wing." He'll next be seen playing New York Yankees owner George Steinbrenner in ESPN's series "The Bronx Is Burning."
His other credits include "The Ice Harvest," "Kinsey" and the short-lived NBC series "Deadline." He's also been cast in the film "Frost/Nixon," Ron Howard's adaptation of the hit play about David Frost's interviews with Richard Nixon.