Sibylle de Saint Phalle learnt her trade in London as press attachee and studio director for Stephen Jones, and then for John Galliano. She then returned to Paris to work at the press office for Comme Des Garcons for five years before working again for John Galliano as director of communications at Givenchy.
During this time she was collaborating with a young designer called Alexander McQueen. In 1999 under Marc Ascoli's leadership she became part of the artistic direction for the Maison Martine Sitbon.
From 2001 Sibylle was casting director for women's ready to wear Hermes, from 2001 to 2004 she was with Martin Margiela, from 2004 until 2010 with Jean Paul Gautier, from 2010 until 2014 with Christophe Lemaire and she now works closely with Nadège Vanhee-Cybulski for the Maison Sellier.
At Guy Laroche, she collaborated with Marcel Marongiu for three years, and then with Adam Andrascik. Sibylle works for Miharayasuhiro for men's ready to wear, and for Christophe Lemaire and Sarah Linh, for both womenswear and menswear. Since 2009 Sibylle has also worked as a stylist (Le Monde d'Hermes, Les Echos, Serie Limitee, Antidote, Vogue Chine, A Magazine).
At different times Sibylle has been muse (she took to the catwalk for Jean Paul Gaultier and inspired John Galliano), studio director (for Stephen Jones and John Galliano), assistant to the artistic director (Marc Ascoli at Martine Sitbon), press attachee (for Stephen Jones, John Galliano and Comme des Garcons), and director of communication (at Givenchy).
She is now devoting her time to her work as a casting director and as a stylist.