"I am still struggling to understand how my lover and best friend could end her life in this tragic way," the Rolling Stones band member wrote on his website in a post titled 'L'Wren'.
Click on the photo below to see a gallery of celebrities wearing L'Wren Scott's designs
"We spent many wonderful years together and had made a great life for ourselves."
His tribute was written below a beautiful picture of the statuesque fashion designer, who had been his partner for nearly 13 years.
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He continued, "She had great presence and her talent was much admired, not least by me.
"I have been touched by the tributes that people have paid to her, and also the personal messages of support that I have received."
Concluding, he said, "I will never forget her."
The rock legend's note came just 24 hours after it was revealed that L'Wren had been found in her Manhattan apartment.
Earlier on Tuesday, it was revealed that the Rolling Stones cancelled their upcoming concert in Perth, Australia.
The band announced they would not be performing the first concert of their Australia tour on Wednesday night as scheduled, via a Facebook message posted on Tuesday afternoon – L'Wren was found on Monday morning.
"We regret to announce that The Rolling Stones concert in Perth will not be going ahead as scheduled for Wednesday 19 March 2014," their promoter Frontier Touring wrote on the social media site.
The Rolling Stones are expected to cancel the rest of the tour, but are yet to make an official statement.
Meanwhile, Mick and Jerri Hall's daughter Georgia May has cancelled her appearance at Melbourne Fashion Week.
The 22-year-old model was set to appear on the Aussie runway for local fashion designer Camilla Franks.
The designer's spokesman said in a statement: "In light of the recent sad news, Georgia May Jagger will not be participating in Virgin Australia Melbourne Fashion Festival for the Camilla Grand Showcase.
"We ask that you respect Ms Jagger and her family’s privacy at this very difficult time."
Father and daughter were both in Australia when they were informed of the tragic news. Georgia had landed in Sydney on Tuesday to take a connecting flight to Melbourne when she was told. She has since flown out of Australia to be with her family in New York.
While The Rolling Stones' jet is still in Perth, it is not known whether Mick and the band have flown out of Australia.
Mick is "shocked and devastated" by the news that his girlfriend of 13 years committed suicide.
The fashion designer was found by her assistant in her Manhattan apartment around 10am New York time on Monday morning. It is understood that the 49-year-old had hanged herself.