Jacob Benjamin Gyllenhaal (pronounced Jill-en-hall) (born December 19, 1980 in Los Angeles, California) is an American film actor. Jake is the son of director Stephen Gyllenhaal and producer/screenwriter Naomi Foner Gyllenhaal, and the brother of actress Maggie Gyllenhaal, who also played his sister in Donnie Darko.
Gyllenhaal made his film debut in City Slickers (1991) and began to establish himself as an up and coming actor in such films as October Sky (1999) before being cast in the title role in Donnie Darko (2001), for which he was nominated for an Independent Spirit Award for best actor. Gyllenhaal's performance as a troubled schizophrenic won him excellent reviews and the film quickly acquired cult status. He played opposite Jennifer Aniston in another Sundance favorite in 2002's The Good Girl and once again earned good reviews. Gyllenhall also starred in the Walt Disney romantic comedy, Bubble Boy. Loosely based on the story of David Vetter, the film portrays the title character's adventure outside the confines of his bubble as he goes after the woman he loves before she marries the wrong man.
Marking his theater debut, Gyllenhaal appeared on the London stage with a starring role in Kenneth Lonergan's revival of This Is Our Youth. The play, which was a critical sensation on Broadway, ran for eight weeks in London's West End. For his role, Gyllenhaal received an Evening Standard Theater Award in the category of "Outstanding Newcomer."