The former singer with 1980s pop group Wham! "passed away peacefully at home," according to the BBC.
Police say the South Central Ambulance Service was called to a property in Oxfordshire, England, just before 2 p.m. on Christmas Day.
Authorities say there are no suspicious circumstances involved.
"It is with great sadness that we can confirm our beloved son, brother and friend George passed away peacefully at home over the Christmas period," the "Freedom" singer's publicist said in a statement.
"The family would ask that their privacy be respected at this difficult and emotional time. There will be no further comment at this stage."
Born Georgios Kyriacos Panayiotou in London, Michael befriended future Wham! bandmate Andrew Ridgeley in high school. They released their first album, Fantastic, in 1983, and found fame in the U.S. the following year with their second album, Make It Big, which spawned the megahits "Wake Me Up Before You Go-Go" and "Careless Whisper."
Michael went solo in 1987, releasing the album Faith, which won a Grammy for Album of the Year, featured hits like "I Want Your Sex" and sold more than 20 million copies worldwide. He went on to sell more than 100 million albums throughout his career.
In 1998 Michael was arrested for engaging in a lewd act in a public restroom in a Beverly Hills park, later pleading no contest to the charge. Before his arrest there'd been speculation about his sexuality, with Michael telling Ridgeley that he was bisexual. After the arrest, he came out as gay, saying in an interview with The Advocate in 1999 that falling in love with a man ended his conflict over bisexuality.
In 2006, he was arrested for possession of Class C drugs, and in 2010 pleaded guilty to driving under the influence of drugs and was sentenced to eight weeks in prison. Michael admitted in an interview in 2009 that he was trying to cut back on his marijuana use. "I'm surprised I've survived my own dysfunction," he told The Guardian.
The singer was admitted to a hospital in Vienna in the middle of his Symphonica tour in 2011. He ended up in the intensive care unit, suffering from pneumonia, and underwent a tracheotomy.
Two years later Michael suffered a head injury when he fell from his moving car on the M1 freeway in the U.K. and was airlifted to a nearby hospital.
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