Originally from Nice, France, Sandrine Cassini studied at the Conservatoire Superieur de Paris. She won the Professional Prize at the Prix de Lausanne at the age of 16 before joining the Paris Opera Ballet.
Cassini then joined Ballets de Monte-Carlo as a first soloist, and went on to perform with Zurich Ballet, Ballet British Columbia, National Theater Mannheim, and Bejart Ballet. She has performed leading roles in works by George Balanchine, William Forsythe, Nacho Duato, Jean-Christophe Maillot, Maurice Bejart, and John Neumeier.
She took up the position of Ballet Mistress with the Royal New Zealand Ballet in 2014, served as guest assistant at the Dresden Frankfurt Dance Company in 2016, and was Rehearsal Director of Ballet British Columbia in 2018. Cassini joined the faculty of SF Ballet School in 2019.