The iconic singer -- best known for his success in the early '80s with Wham! and then a solo career that kicked off with the hit, "Careless Whisper" -- died on Sunday at his home in London. He was 53.

NEWS: George Michael Dies at 53

Michael's good friend, Elton John, took to Instagram to honor the late singer.

"I am in deep shock. I have lost a beloved friend - the kindest, most generous soul and a brilliant artist," John wrote alongside a photo of him and Michael. "My heart goes out to his family and all of his fans. @GeorgeMichael #RIP."

British actor Ricky Gervaias was one of the first to post on social media, where he alluded to how difficult 2016 has been. "Unbelievable," he tweeted. "RIP George Michael."

Unbelievable.
RIP George Michael.

— Ricky Gervais (@rickygervais) December 25, 2016

And supermodel Linda Evangelista, who starred in the music video for Michael's iconic "Freedom! '90," shared a black-and-white photo with the singer on Instagram.

"I am beyond heartbroken and devastated by another tragic loss," she captioned the pic. "R.I.P. dearest Georgy."

I am beyond heartbroken and devastated by another tragic loss. R.I.P. dearest Georgy. #GeorgeMichael #ripgeorgemichael

A photo posted by Linda Evangelista (@lindaevangelista) on

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See how other stars have reacted to the news:

Dear George the angels will love you We will miss you

A photo posted by @helenmirren on

Man, I loved his music. One of my all time favorites. Gone too soon. #RIPGeorgeMichael

A photo posted by Candace Cameron Bure (@candacecbure) on

Had the pleasure of knowing George Michael in the 80s. Voice of an angel. Now he can sing for them.

— Rob Lowe (@RobLowe) December 26, 2016

#RIPGeorgeMichael. You were an absolute genius. My sincerest condolences go out to your family, David, Michael and your whole team

— Nile Rodgers (@nilerodgers) December 26, 2016

I was just at his home the morning of our last @CHICorg show on Dec 23rd in London. I'm stunned #RIPGeorgeMichael My heartfelt condolences.

— Nile Rodgers (@nilerodgers) December 26, 2016

RIP George Michael

— Russell Crowe (@russellcrowe) December 25, 2016

absolutely devastated about george michael. what a fucked up way to end this year. rest in peace my friend....

— Belinda Carlisle (@belindaofficial) December 26, 2016

I can't deal with this. One of my ALL TIME favorites. RIP George Michael and I really hate writing that so much. https://t.co/1cRJBMgYga

— billy eichner (@billyeichner) December 25, 2016

God Bless George Michael , Say a prayer for him . A nice human .
M

— Meat Loaf (@RealMeatLoaf) December 25, 2016

My god. Rest in paradise @GeorgeMichael--an icon, an ally, a legend. pic.twitter.com/MfxPVFG0B2

— Margaret Cho (@margaretcho) December 25, 2016

Miss you already! Thank you for your radical activism in the LGBTQ community! Love you always! @happyhippiefdnpic.twitter.com/nBCxjEstDo

— Miley Ray Cyrus (@MileyCyrus) December 26, 2016

10 Christmases ago today James Brown died. Today, George Michael... RIP...

— Talib Kweli Greene (@TalibKweli) December 26, 2016

I've loved George Michael for as long as I can remember. He was an absolute inspiration. Always ahead of his time.

— James Corden (@JKCorden) December 25, 2016

George Michael wrote Praying for Time 25 years ago but I truly believe it's message means more now than ever. https://t.co/f03zlWYbLa

— James Corden (@JKCorden) December 25, 2016

RIP George Michael. I can't believe it. Such an incredible singer and a lovely human being, far too young to leave us #georgemichael

— Bryan Adams (@bryanadams) December 25, 2016

Rest peacefully George Micheal