38 years old (Born on December 19, 1980)
American actor; He is famous from Donnie Darko.Campaigned for the Democrats in the 2004 US election. Played brother to real life sister Maggie Gyllenhaal in their movie Donnie Darko (2001). Voted #10 in Elle (France) Magazine's "15 Sexiest Men" poll (June 2007). His favorite book is To Kill a Mockingbird, and he has two dogs, Atticus and Boo named after the novel`s main characters. Uncle of Ramona Sarsgaard, born October 3, 2006. She is the daughter of his older sister Maggie Gyllenhaal and Peter Sarsgaard.
Jake Gyllenhaal's Best Moments
Fun Facts About Jake Gyllenhaal
When asked who his idols are he said Anthony Quinn, Paul Newman, Sean Penn, Bruce Springsteen and Bono.
Like all Gyllenhaals on the male line, he is a Swedish nobleman by birth right and is listed in the Swedish Almanac of Nobility ("Sveriges Ridderskaps och Adels Kalender" in Swedish).
Received his first driving lesson from Paul Newman.
Godmother is Jamie Lee Curtis.
Spent two years at Columbia University, where one of his professors was Robert Thurman, Uma Thurman`s father.
Very good friends with actress Jennifer Aniston.
He gave Kirsten Dunst a gray and white kitten for her birthday. She named the cat Sophie.
Invited to join AMPAS in 2006.
is a fan of the Boston Red Sox baseball team
Graduated Harvard-Westlake (private) high school. 
Is of Swedish (noble) and Russian-Jewish descent.
Was set to play Spiderman in Spider-Man 2 (2004) due to complications with Tobey Maguire. While he was preparing for the role, Maguire was back as Spiderman.
Studied acting with Ivana Chubbuck.
Auditioned for and was one of the top contenders for the role of Batman/Bruce Wayne in Batman Begins (2005).
Sister Maggie Gyllenhaal introduced him to Kirsten Dunst. Both Kirsten and Maggie appeared in Mona Lisa Smile (2003). Jake and Kirsten dated, but broke up in July 2004.
Before success as an actor, he worked as a lifeguard. He never had any life-saving incidents, but did perform one lesser rescue. A swimmer had been stung on the leg by a jellyfish, and Gyllenhaal helped relieve the pain of the stings by urinating on the swimmer`s leg.
Went to elementary school with band members of Maroon 5.
He appeared in a 1994 episode of "Homicide: Life on the Street" (1993) that was directed by his father, Steven.
On Phantom Planet's album "The Guest", lead singer Alex Greenwald lists him in his thank yous. Alex appeared with Jake in Donnie Darko (2001).
Was named one of People Magazine`s 50 Hottest Bachelors .
Was among the guests at Jessica Simpson`s 25th birthday party.
Had his Bar Mitzvah party at a homeless shelter, something his parents encouraged to help him recognize how privileged his own childhood had been (a Bar Mitzvah is the coming-of-age service that Jewish boys celebrate at age 13).
Attended high school with "Freaks and Geeks" (1999) star Jason Segel.
Ranked #48 on Premiere's 2006 "Power 50" list. It is his first appearance on the list.
Gained five pounds of muscle for his role in Jarhead (2005).
His uncle, Anders Gyllenhaal, is editor-in-chief of the Star Tribune newspaper in Minneapolis.
His fans refer to themselves as "Gyllenhaalics".
Shares his birthday with Marla Sokoloff, Alyssa Milano, Jennifer Beals and u00c9dith Piaf.
Dropped out of Columbia University after two years (2002).
Along with sister, Maggie Gyllenhaal, he attended Camp Walt Whitman, an outdoors summer camp in Western New Hampshire.
Is good friends with Lance Armstrong, Matthew McConaughey and Nick Dash .
Is close friends with Natalie Portman and Bryce Dallas Howard.
Was personally approved by Joe Namath to play the football legend in an upcoming biopic about the latter's life.
His first four big roles were in movies with alliterated titles: Bubble Boy (2001), Donnie Darko (2001), Moonlight Mile (2002), The Good Girl (2002).
He was awarded the 2002 London Evening Standard Theate Award for Outstanding Newcomer for his performance in This is Our Youth at the Garrick Theatre in London, England.
As of 2007, has starred in three movies where he played not only a real person, but the person who wrote the book upon which the film was based: Homer Hickham (October Sky), Anthony Swofford (Jarhead) and Robert Graysmith (Zodiac).
Godfather is Paul Newman.
Godfather of Matilda Rose Ledger, born October 28, 2005 (daughter of actor Heath Ledger and actress Michelle Williams.
His last name is pronounced Jill-en-hall.
Son of director Stephen Gyllenhaal and screenwriter Naomi Foner. Younger brother of Maggie Gyllenhaal. His godmother is Jamie Lee Curtis and godfather is Paul Newman. He received his first driving lesson from Newman.
Although they broke up in July 2004, he and Kirsten Dunst still have an on and off relationship.