Stars of stage and screen - including Will Smith who played him in the biopic Ali - have been paying tribute to Muhammad Ali, who has died at the age of 74.
Will Smith, the actor who played the legendary boxer in the biopic Ali - has also paid tribute. "You shook up the World!" he wrote on Facebook. "My Mentor & My Friend. You changed my Life. Rest in Peace."
Ali, a three-time world champion, passed away in hospital in Phoenix, Arizona on Friday following a 32-year battle with Parkinson's disease.
Madonna, echoing the thoughts of so many, described Ali as "The Greatest". "He shook up the World! God Bless Him," she wrote on Instagram, posting pictures of herself with the sporting and cultural icon.

"Nobody will ever come close to this man's greatness," said Irish UFC champion Conor McGregor. "And if they do, they better wake up and apologise."
Talk show host Oprah Winfrey said the world had lost a legend and a real champion. Beatles great Ringo Starr wrote: "God bless Muhammad Ali peace and love to all his family", while singer Lionel Richie described Ali as his hero.

Oscar winner Halle Berry described Ali as "one of the strongest and sweetest men I ever met". "He elevated the sport of boxing and there will never be another," she added.
Carl Weathers, who played boxer Apollo Creed in the Rocky movies, said: "The Greatest made the world a better place. His work is done. We are better for it." Mark Wahlberg, who portrayed former light welterweight champion Micky Ward in the Oscar-winning film The Fighter, said that Ali's legacy extended beyond sports.
A gem - one of many - from Cathal O'Shannon's interview with Muhammad Ali on @rte in 1972.https://t.co/KMZE6sx8rT
— RTÉ TEN (@RTE_TEN) June 4, 2016
Director Michael Moore said that Ali's courage in standing up to those in power would never be forgotten. "You gave up your title and your career rather than kill Vietnamese," he added in reference to Ali's opposition to the Vietnam War and his refusal to serve.
Unsurprisingly, he said it best himself. #MuhammedAli pic.twitter.com/G1BykvvzfF
— J.K. Rowling (@jk_rowling) June 4, 2016
As a tribute to Muhammad Ali, RTÉ One will screen the documentary When Ali Came to Ireland on Sunday at 7:30pm.

Lenny Kravitz shared this photo on Instagram
Just some of the other tributes to Muhammad Ali:
You will always be my hero ... #MuhammadAli pic.twitter.com/Rbp7Be3JAK
— Lionel Richie (@LionelRichie) June 4, 2016
For the greatest man I have ever known. https://t.co/OUZHVZWBHY — Billy Crystal (@BillyCrystal) June 3, 2016
I had the honor of knowing #Muhammad Ali. He was simply The greatest inspiration to the whole world. Sad sad day.
— David Hasselhoff (@DavidHasselhoff) June 4, 2016
Rest in peace Champ. #Alifelived #Champ #truelegend #muhammadali #floatlikeabutterfly… https://t.co/3jJRtUAZBn
— Ronan Keating (@ronanofficial) June 4, 2016
"Float like a butterfly, sting like a bee" RIP #MuhammadAli 😢
— Joan Collins (@Joancollinsdbe) June 4, 2016
You can change the world. #MuhammadAli
— Jeff Daniels (@Jeff_Daniels) June 4, 2016
I mourn the passing of #MuhammadAli. He was indeed "The Greatest." An American legend & a true Champion for the world. #RIPMuhammadAli
— Larry King (@kingsthings) June 4, 2016
#my2heros ❤️❤️❤️❤️❤️❤️❤️❤️❤️🙌🏾🙌🏾🙏🏾🙏🏾 pic.twitter.com/nOweammxHB
— Naomi Campbell (@NaomiCampbell) June 4, 2016
In a year where many greats have passed, the greatest of all has just left us. Goodbye champ. Fly like a butterfly. pic.twitter.com/S5Hc992tvY
— Josh Gad (@joshgad) June 4, 2016
The Greatest made the world a better place. His work is done. We are better for it. Thank you. RIP, Champ. #BePeace pic.twitter.com/VtPhYRJS3U — Carl Weathers (@TheCarlWeathers) June 4, 2016
#RIPMuhammadAli pic.twitter.com/4raRK0J28Q — PUBLIC ENEMY (@PublicEnemyFTP) June 4, 2016