Born Renée Mézière in Paris, she modelled for Balenciaga and Givenchy before turning to design, taking the professional name Emmanuelle. In 1962, with Christiane Bailly, she launched her first collection under the label Emma Christie; she was soon compared to Mary Quant and seen as a French counterpart to the London Mod movement. By 1964 her business fetched $4 million a year, and she was credited with bringing "class and status" to French ready-to-wear, signing an exclusive contract with New York's Henri Bendel.
She designed for youth-oriented labels including Missoni, Krizia and Cacharel, and in 1971 was, with Ossie Clark, a founding member of Didier Grumbach's Créateurs et Industriels. That year she founded her own company, Emmanuelle Khanh Paris, opening her first eponymous boutiques in 1977. The company closed in the late 1990s and the brand was sold in 2007 to a Dutch conglomerate.