Fans have been laying floral tributes in front of his home in Goring while charities involved with helping children, cancer victims and AIDS sufferers have revealed the artiste's his generous donations running up to millions of dollars.
Michael's Australian-born boyfriend Fadi Fawaz has tweeted of his grief, indicating he found the artist "dead peacefully in bed first thing" Christmas morning.
Former Wham! bandmate Andrew Ridgeley said he was "heartbroken at the loss of my beloved friend", while Sir Elton John mourned a "brilliant artist".
George Michael's former long-term partner Kenny Goss paid tribute to an "extremely kind and generous man", saying he "loved him very, very much".
The star had "passed away peacefully" on Christmas Day in Goring-on-Thames, Oxfordshire, Michael's publicist said in a statement.
His manager, Michael Lippman, said the singer had died of heart failure.
Scores of celebrities and fans have taken to social media to pay tribute to the pop star.
Michael, who was born Georgios Kyriacos Panayiotou in north London, sold more than 100 million albums throughout a career spanning almost four decades.
(Excerpts from BBC News)