Jack Gyllenhaal is an American actor born on December 19, 1980, in Los Angeles, California. He comes from a family involved in the film industry, with his father being a director and his mother a screenwriter. Gyllenhaal gained fame for his roles in films like Donnie Darko and Brokeback Mountain, showcasing his versatility as an actor. Throughout his career, Gyllenhaal has received critical acclaim and several award nominations, including Academy Awards and Golden Globes. He is known for his dedication to his roles, often undergoing significant physical transformations for films such as Nightcrawler and Southpaw.