Muhammad Ali has died at the age of 74.
The three-time world heavyweight champion was admitted to hospital earlier in the week with a respiratory condition.
Ali, who was diagnosed with Parkinson's Disease 32 years ago, is widely considered to be one of the greatest heavyweights in boxing history.
His family's spokesman Bob Gunnell confirmed Ali's death in Phoenix, Arizona, on Friday evening local time.
A statement read: "The Ali family would like to thank everyone for their thoughts, prayers, and support and asks for privacy at this time."
Ali's funeral will take place in his hometown of Louisville, Kentucky.
Earlier his daughter, Laila Ali, shared a touching photo on social media and thanked fans for their support.
The 38-year-old posted on her official Facebook page: "I love this photo of my father and my daughter Sydney when she was a baby!
"Thank for all the love and well wishes. I feel your love and appreciate it!!"
Ali, who retired from the ring in 1981, was last admitted to hospital in January 2015 with a severe urinary tract infection.