In what will be her first TV series gig in the U.S., Toni Collette has signed on to star in Steven Spielberg’s Showtime comedy pilot “The United States of Tara.”

Thesp is aboard to play Tara Gregor, a wife and mother of two teenage kids who seems normal on the surface but actually suffers form dissociative identity disorder.

Dark half-hour comedy will follow Tara as she deals with her various personalities — in the pilot, they include a teen girl and adult man — as they emerge during times of stress.

Project came from an original Spielberg idea, repping his first series project for Showtime and his first comedy project in TV. Feature scribe Diablo Cody (“Juno”) is writing and exec producing, while DreamWorks TV’s Justin Falvey and Darryl Frank are also exec producers.

Spielberg will decide after the pilot what his credit will read.

Showtime entertainment prexy Robert Greenblatt said Collette topped his wishlist of actresses to play Tara.

“When you’re casting a show that requires an actress to not only play one complex character but in this case several, the road begins and ends with Toni Collette,” said Greenblatt, who called the thesp “one of the best young actresses of her generation.”

Collette will next be seen in the Alan Ball feature “Nothing Is Private” and the Australian kids film “Hey, Hey It’s Esther Blueburger.”

Collette’s recent features include “Little Miss Sunshine” and “Evening.”