He graduated from the Ecole Nationale Supérieure des Arts Décoratifs Paris, in 1968, after completing the very first course in industrial design. After completing his studies, he and a group of friends cofounded the Design Centre Premier, the first group of associate designers in France. During this time he collaborated with important brands in the fashion industry such as Pierre Cardin, Ted Lapidus, Torrente and Yves Saint Laurent.
Between 1973 and 1974 Sadler established partnership with some of the main Italian sports companies such as Lotto, being responsible for designing all products and logos. During those years, Dainese, Nordica, Reebok, Nike, and Foot Joy were other very important partners, both in Italy and abroad.
In 1978 Marc started his own business in New York City, creating a new line of shoes for Dainese, leader in the market for motorcycle apparel and accessories. In 1983 Marc designed a collection of shoes for Ellesse. Thanks to the success of the Dainese and Ellesse collections, Marc became known as the most innovative sport shoe designer. He also designed a shoe for Nike, the first water-repellent thermo plastic rubber, still one of the mostly sold Nike products worldwide.
As a sample of his design versatility and transversal specialization, Marc Sadler along the years collaborates with main companies operating in different industries such as Watco, Matrix, Beretta and ABB Sace.