Brother of Shannon Leto.
His hobbies include snowboarding, skateboarding, hiking, writing songs, reading, and painting.
Is in a band called 30 Seconds to Mars with his brother Shannon Leto and Tomo Milicevic. The band has three albums out; their self-titled debut album, their second album is entitled "A Beautiful Lie" and the third one is named "This Is War".
Jared`s favorite foods are popcorn and vegetables, and his favorite drink is hot chocolate.
While preparing for his role as a heroin addict in the movie Requiem for a Dream (2000), Jared lost 28 pounds, starved himself and denied himself the pleasure of then-fiancée Cameron Diaz`s bed for two months. Leto admits that playing the part of Harry Goldfarb was "sadomasochistic... the hardest thing I`ve done".
Attended the University of the Arts in Philadelphia.
In many of his movies, he is disfigured in some way. In Requiem for a Dream (2000), his arm becomes infected and is amputated. In Fight Club (1999), his face is beaten beyond recognition. In Panic Room (2002), he is badly burned. In American Psycho (2000), he is brutally murdered with an ax.
Transfered from UARTS in Philly to School of Visual Arts in Manhattan to study Film and Video.
Does not eat red meat, but is known to eat eggs. He has been said to be a vegan which is misconception, as vegans do not eat eggs but vegetarians do.
He gained 62 lb for his latest role, playing Mark David Chapman, in Chapter 27 (2007). Then lost the weight by going on an all-liquid diet consisting of lemon juice, maple syrup, cayenne pepper, and water. He lost 20 lb in 10 days.
Has been diagnosed with gout after undergoing dramatic weight loss. He packed on 62 pounds for his role in Chapter 27 (2007) [August 2006]
He turned down a key role in Flags of Our Fathers (2006) in order to commit his time to his band, 30 Seconds to Mars.
Had a part in Phone Booth (2002) which was deleted from the final cut.
He has two younger half-brothers from his father`s second marriage.
Was writer/director Joby Harold`s first choice to play Clayton Beresford, the male lead in 2007`s "Awake". He later backed out due to scheduling conflicts with his band, 30 Seconds To Mars, and was replaced by Hayden Christensen.
For most shows, Leto uses either one of two custom-made Steve McSwain guitars, a white one called "Pythagoras" or a black one called "Artemis". The guitars— identical except that one is black and the other white — have the image of a gryphon which he drew for McSwain.
Leto directed the videos for the songs "The Kill" and "From Yesterday" under the alias of Bartholomew Cubbins , and "A Beautiful Lie" under the alias of Angakok Panipaq .
For Lord of War he Learned Russian for this role.
For Mr. Nobody he Speaks French in this role.
Was engaged to Cameron Diaz. [2000-2002]
Had a dog named Judas who died in May 2007.
Chosen as one of People Magazine`s 50 Most Beautiful People. 
Chosen by "People" magazine as one of the 50 Most Beautiful People in the World.