Michael rose to fame with the band Wham with his school friend Andrew Ridgeley, before he went solo in 1986, producing his best known hits "Last Christmas", "Freedom", "Careless Whisper" and "Wake Me Up Before You Go Go".
George Michael (R) and Andrew Ridgeley of pop group Wham! (Getty)
Singer Elton John posted a picture of himself with Michael on Instagram with a caption: "I am in deep shock. I have lost a beloved friend - the kindest, most generous soul and a brilliant artist."
Madonna posted a video of herself presenting Michael with an award and wrote: "Farewell my Friend! Another Great Artist leaves us."
Duran Duran, Michael's contemporary in the 1980's posted on the official Twitter account, "2016 - loss of another talented soul. All our love and sympathy to George Michael's family."
Messages for the pop star also poured from outside the music faternity with Star Trek actor George Takei paying tribute by remembering his greatest hits: "Rest with the glittering stars, George Michael.You've found your Freedom, your Faith. It was your Last Christmas, and we shall miss you."
British singer George Michael performs during the closing ceremony of the 2012 London Olympic Games at the Olympic stadium in London on August 12, 2012. (AFP)