Delphine Jelk is a Swiss-born perfumer who reached fragrance through fashion. Born in Switzerland, she trained first in fashion design at ESMOD in Paris, where her graduate collection paired each garment with a scent, a project that pointed her toward perfumery. She went on to study at the Grasse Institute of Perfumery (GIP) and worked in trend research and evaluation at Firmenich in Geneva and Paris before moving into composition itself.

Her formation as a perfumer took shape under the mentorship of Philippe Romano, and she developed fragrances at Drom before her path led to Guerlain. Her breakthrough came with La Petite Robe Noire, a playful gourmand built around a fruity, macaron-like accord that became a worldwide bestseller and helped redefine the house's mainstream identity. She joined Guerlain as a house perfumer, working alongside in-house master perfumer Thierry Wasser.

At Guerlain she has contributed across the range, from the Aqua Allegoria line to the more rarefied L'Art et la Matière collection, with creations such as Néroli Plein Sud, Patchouli Paris, Musc Outreblanc and L'Heure Blanche. Her compositions are often described as warm and enveloping, drawing on iris, musks and powdery, milky facets. In 2021 she was named Chevalier de l'Ordre des Arts et des Lettres by the French Minister of Culture, recognizing her standing in contemporary French perfumery.