Scott was found dead inside her Manhattan apartment Monday morning, the New York Post reports. She was 49.
"We confirm the tragic death of L’Wren Scott," her publicist says in a statement. "At this devastating time for Ms. Scott’s family and friends, we request that their privacy be respected. There will be no further public statement for the time-being."
"A 49-year-old female was found unconscious and non-responsive by police at 10:05 a.m.," says a spokesperson for the NYPD. "EMS responded and found her deceased. An investigation is ongoing and a medical examiner will determine cause of death."
The longtime girlfriend of rocker Mick Jagger, Scott dressed A-list stars like Nicole Kidman, Sarah Jessica Parker and Olivia Wilde in her gowns.
Raised in Utah as Luann Bambrough, she reinvented herself as a model in Paris and later became a stylist to the stars in the '90s, according to a 2009 Daily Beast interview.
Jagger has been touring in Asia and is scheduled to begin touring in Australia. A spokesman said he is completely shocked and devastated by the news.
Reporting by STEPHANIE PFEFFER, GILLIAN TELLING and BRONWYN BARNES