Multi-faceted comedian and actor Eddie Izzard and multiple award-winning actress Frances Conroy will guest star on the Showtime series United States of Tara. Izzard will appear in eight episodes and Conroy in one episode of the third season opposite Toni Collette, last year's Emmy Award winner and this year's Emmy nominee for her role as Tara Gregson, a wife and mother who struggles with Dissociative Identity Disorder (DID). Izzard will play Tara's brilliant psychology professor who is at first a DID skeptic, but becomes fascinated with Tara as a subject, leading him to further explore the condition. Conroy will star as Max Gregson's (John Corbett) mother, a recluse with a compulsive hoarding problem. Production on season three begins mid-September in Los Angeles for a 2011 premiere.

Eddie Izzard has been hailed as one of the foremost stand-up comedians of his generation. Since his first stage appearance in London's West End in 1993 in the one-man show "Live At The Ambassadors," there have been a succession of sell-out and critically-acclaimed international tours, including "Unrepeatable" in 1994; 1996's "Definite Article;" "Glorious" in 1997; "Dress to Kill" in 1998; 2000 was the year of "Circle," and "Sexie" followed in 2003. Izzard's latest stand-up show, "Stripped," broke box office records with a UK, U.S. and European arena tour. This year, Izzard performed a series of South African dates in support of Nelson Mandela's 46664 Charity.

While initially renowned as a comedian, Izzard is also now equally respected as a film, theatre and TV actor. His hugely successful FX drama series The Riches, has been critically acclaimed across the world. His stage appearances include Mamet's "The Crypotogram;" "900 Oneonta;" the title role in Marlowe's "Edward II;" and "A Day in the Life of Joe Egg" in London and on Broadway, which won him several prestigious awards including a Tony Award nomination. His movie credits include Secret Agent, Ocean's Twelve and Ocean's Thirteen, Across the Universe, Rage, Valkyrie, among others. In 2009, Believe: The Eddie Izzard Story, had its international theatrical release, documenting Izzard's life as a young street performer during the 1980s to the comedian, actor, political activist he is now recognized as. The film garnered an Emmy nomination for Outstanding Nonfiction Special.

A graduate of The Juilliard School's Drama Division, Frances Conroy is a three-time Emmy nominee, Golden Globe and Screen Actors Guild winner for her role on the hit series Six Feet Under. Conroy's television credits also include the miniseries Queen, Murder in a Small Town, and guest roles on ER, Desperate Housewives, How I Met Your Mother, Nip/Tuck and Happy Town. In theatre, she has been in multiple productions at Joseph Papp's Public Theatre and Lincoln Center including "Our Town," first performed on Broadway and then taped for PBS' "Great Performances." Conroy was also in "The Lady From Dubuque" and "Three Tall Women." She received an OBIE Award for Arthur Miller's "The Last Yankee" and a Tony Award nomination for "The Ride Down Mt. Morgan." She has received four Drama Desk Award nominations, and garnered the award for David Hare's "The Secret Rapture." She was last seen in the 2006 Mark Taper production of "Pyrenees."

Conroy has appeared in numerous films including Manhattan, Another Woman, Crimes and Misdemeanors, The Aviator, The Neon Bible, Scent of a Woman, Dirty Rotten Scoundrels, Catwoman, Shopgirl, Broken Flowers, and independent features such as Ira & Abby and Humboldt County. This year, Conroy portrays Robert De Niro's wife in the upcoming John Curran's Stone and stars opposite Kris Kristofferson in Provinces of Night.

United States of Tara stars Oscar nominee Toni Collette, last year's Emmy and Golden Globe Award winner, and this year's Emmy nominee for her role as "Tara," a woman who juggles being a suburban wife, mother and sister while also having DID (dissociative identity disorder), formerly known as multiple personality disorder. Executive produced by DW Studios L.L.C. and created by Diablo Cody, the series delves into how a family copes with the various alters that may appear on any given day and range in age, temperament and even gender.