Jagger's bandmates voiced their support for him amid a trying time.
Keith Richards said in a statement Wednesday that "no one saw this coming" and that Jagger has "always been my soul brother and we love him."
"We're thick as thieves and we're all feeling for the man," he added.
Charlie Watts said the band's priority is the 70-year-old Jagger.
"Needless to say we are all completely shocked but our first thought is to support Mick at this awful time," he said. "We intend to come back to Australia and New Zealand as soon as it proves possible."
Ronnie Wood echoed Watts' statement.
"This is such terrible news and right now the important thing is that we are all pulling together to offer Mick our support and help him through this sad time," Wood said. "Without a doubt we intend to be back out on that stage as soon as we can."
Scott had been Jagger's companion since 2001. The Rolling Stones frontman paid tribute to his girlfriend Tuesday on his Facebook page writing, "I will never forget her."
"I am still struggling to understand how my lover and best friend could end her life in this tragic way. We spent many wonderful years together and had made a great life for ourselves. She had great presence and her talent was much admired, not least by me."
The fashion label founded by Scott had been heavily in debt and was reportedly about to fold.
Former New York Times fashion writer Cathy Horyn said in an essay on the paper's website that Scott had been planning to announce that she was closing her business.
Scott canceled her London Fashion Week show last month, citing production delays.
Scott launched her high-end fashion label in 2006. First lady Michelle Obama, Nicole Kidman and Penelope Cruz were among the big names to wear her designs.
Accounts filed by Scott's LS Fashion Ltd. in London show the company had liabilities that exceeded assets by 4.24 million euros ($5.9 million) as of Dec. 31, 2012.