The producer, who worked on Winehouse's Back to Black album, reacted to the singer's passing on his Twitter account.
He tweeted: "she was my musical soulmate & like a sister to me. this is one of the saddest days of my life."
Ronson's production on Back to Black won him the Grammy for 'Producer Of The Year' in 2008. The pair also teamed up on Zutons cover 'Valerie' for Ronson's second studio album Version.
Winehouse was found dead at her Camden, North London home on Saturday afternoon. Police are currently treating the death as "unexplained".
> Obituary: Amy Winehouse
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Watch the video for Amy Winehouse and Mark Ronson's 'Valerie' below: