The actor is a family friend and portrayed the boxing icon in his 2001 biopic.
Will Smith will play a key role at Muhammad Ali's memorial service.
The actor has been announced as one of eight funeral pallbearers, alongside Ali's family members, friends, former heavyweight champion of the world Lennox Lewis, and Jerry Ellis, the brother of Ali's former sparring partner and fellow former heavyweight champion of the world, Jimmy Ellis. The service is set for Friday, June 10, at KFC Yum! Center in Ali's hometown of Louisville, Kentucky, from 2 p.m. to 4 p.m.
As ET previously reported, Billy Crystal and president Bill Clinton are among those expected to deliver eulogies at the service.
WATCH: Will Smith Pays His Respects to Muhammad Ali - 'You Changed My Life'
Smith portrayed the legendary fighter in the 2001 biopic, Ali. The part earned Smith his first Academy Award nomination, though the trophy that year ultimately went to Denzel Washington for Training Day.
After news of Ali's death broke on Friday, the 47-year-old star took to Facebook to remember his friend.
"You shook up the World!" he wrote. "My Mentor & My Friend. You changed my Life. Rest in Peace."
Just last year, Smith honored Ali at Sports Illustrated's Sportsperson of the Year ceremony, where the Legacy Award was renamed the Sports Illustrated Muhammad Ali Legacy Award.
"There's no doubt that he was a great boxer. He was the greatest of all time," Smith said. "When we think about the legacy of Muhammad Ali, what he did in the ring is not what we think about."
"For nearly two years, I worked to transform myself into the man who changed his name from Cassius Clay to Muhammad Ali and shook up the world, and that’s really what makes my job so beautiful," he continued. "As an actor, for four or five months at a time, I get to wear people's lives, so I got to wear Muhammad Ali's greatness. I got to study and feel and embody the soul of the man from the foundations of Islam and the strength of his Muslim faith in his life to the beautiful wake that he always leaves in his magnificent path."
Ali followed a decade of the champion athlete's life starting in 1964, which included his heavyweight title fight against Sonny Liston and being banished from the sport following criticism of the Vietnam War. As for Sports Illustrated, the magazine has named Ali, whose nickname was "The Greatest," the Sportsman of the Century.
Ali died at the age of 74 on Friday following a 32-year battle with Parkinson's disease.