The Famous Jett Jackson actor's longtime manager, Jonathan Baruch, told E! News that the 29-year-old "tragically took his own life this morning."
He added, "Lee was more than just a brilliant young actor, he was a wonderful and gentle soul who will be truly missed. We ask that you please respect the privacy of his family and friends at this very difficult time."
Costars of the actor have come forward via Twitter to send their condolences to the Young's friends, family and loved ones.
Take a look at what more stars had to say:
Harry Shum Jr.: Feeling incredibly sad about Lee Thompson Young. My heart goes out to his family and friends. #gonetoosoon
Columbus Short: My heart is broken today. RIP to my friend and brother Lee Thompson Young. Writing partner/Friend/Brother #HeartAche
Wes Craven: My sympathy to the family of Lee Thompson Young and to all who knew and loved him.
If you or someone you know needs help, please call the National Suicide Prevention Lifeline at 1-800-273-TALK (8255).