Britain's former world heavyweight champion Lennox Lewis and actor Will Smith will be pallbearers at Muhammad Ali's funeral on Friday.
London-born Lewis, 50, became undisputed world champion in 1999, while American Smith, 47, played Ali in the 2001 film of the same name.
Three-time heavyweight world champion Ali died last Friday at the age of 74 in hospital in Phoenix, Arizona.
His funeral will be held in his home town of Louisville, Kentucky.
"I am humbled, and honoured, beyond words to help see my hero, Muhammad Ali, off to his final resting place," said Lewis, in a statement.
"Ali has always been an enormous inspiration to me, not only in my boxing career, but also in life. His journey began 74 years ago, and in that time, he not only transformed the world of sport, he used sport to transform the world."
The other pallbearers will be Jerry Ellis, the brother of Jimmy Ellis, Ali's former sparring partner and fellow world heavyweight champion, Ali's cousins John Grady and Jan Wadell, nephew Ibn Ali, former brother-in-law Komawi Ali and family friend John Ramsey.
Friday's service, which will be attended by a number of world leaders, heads of state and celebrities, will be open to the public and streamed live on the internet. It starts at 19:00 BST.