Carlos Benaïm grew up in Tangier, Morocco, where his father's work as a pharmacist first exposed him to essential oils and plant distillation. He went on to study chemistry and chemical engineering in Toulouse, France, and it was a summer placement in nearby Grasse — perfumery's historic capital — that turned his technical training toward scent.

In 1967 he answered a recruitment ad in Le Monde and joined International Flavors & Fragrances as a trainee perfumer, one of a small group chosen from hundreds of applicants. At IFF he apprenticed under senior noses Ernest Shiftan, Bernard Chant, and Max Gavarry, absorbing a house style built on precise materials and emotionally legible compositions. He remained with IFF for the whole of his career, and in 2013 the company named him its first-ever Master Perfumer, a title created to recognize his standing within the firm.

Over five decades Benaïm built one of the most commercially influential portfolios in modern perfumery, composing scents such as Ralph Lauren's Polo, Calvin Klein's Eternity for Men and Euphoria, Elizabeth Taylor's White Diamonds, Bulgari's Jasmin Noir, Boucheron's Jaipur Bracelet, and Yves Saint Laurent's Libre, alongside Viktor & Rolf's Flowerbomb, which he created together with Olivier Polge and Domitille Bertier. In parallel with this mainstream output he has also worked on smaller, artisanal projects, including pieces for Frédéric Malle and the American niche house Maison d'Etto.

His work has been recognized with the American Society of Perfumers' Lifetime Achievement Award in 2004 and The Fragrance Foundation's Perfumer of the Year Lifetime Achievement Award in 2014. Benaïm has spoken about composing toward what he calls the 'olfactory image' — the lasting impression a scent leaves behind — treating fragrance creation as an interplay of memory, feeling, and technical craft rather than formula alone.