EXCLUSIVE: Saoirse Ronan is set to star in Lady Bird, the writing and directorial debut of actress Greta Gerwig. IAC Films is financing the film, which is being produced by Scott Rudin, Eli Bush and Evelyn O’Neill. Ronan will play a high school senior, spending her last year at home in Sacramento. Deal comes as Ronan was just Oscar nominated for Best Actress for her performance in Brooklyn, the John Crowley-directed film that debuted at Sundance last year. It’s her second Oscar nom, following her breakthrough turn in Atonement. Ronan also got Golden Globe, BAFTA and SAG nominations for Brooklyn, which was released November 4 by Fox Searchlight.

Ronan will work this around her Broadway debut this spring in Arthur Miller’s classic drama The Crucible, which Rudin is also producing. She recently wrapped an adaptation of Anton Chekhov’s The Seagull, and was last seen in Wes Anderson’s The Grand Budapest Hotel. Ronan is represented by CAA and Macfarlane Chard.

Gerwig is getting behind the camera after co-writing with director Noah Baumbach Mistress America, a film she starred in. Gerwig is also starring in Jackie, the drama that chronicles Jacqueline Kennedy’s four nightmare days following the assassination of her husband, John F. Kennedy. She is also part of the ensemble cast of Weiner-Dog, which premieres here at Sundance, and plays the title role in Rebecca Miller’s Maggie’s Plan. Gerwig is repped by UTA, Management 360 and Felker Toczek Suddleson Abramson.