Introduced to Art Nouveau by Emile Gallé in 1894, Majorelle became in February 1901 one of the founding members of the École de Nancy, previously known as the Alliance provinciale des industries d'art, bringing together a group of artists, architects, art critics and industrialists from Lorraine, who decided to work collaboratively with a predominance for Art Nouveau. Led by Émile Gallé (until his death in 1904), and then by Victor Prouvé, its members joined together for various reasons, notably to ensure a high level of quality in the decorative arts in the region where the main manufacturers were based.

Majorelle was one of the vice presidents of the group from its foundation, remaining so throughout the duration of the École de Nancy, of which he is considered one of the leading figures. Mainly, he and the other members promoted the work of Lorraine's decorative artists, promoting and setting up a school for industrial arts, participating in important exhibitions (including their own), and collaborating to produce individual elements and buildings, mostly in the Art Nouveau style. They thus achieved a unity in the art and architecture produced by the Lorrainers.

Majorelle is undoubtedly one of the internationally recognized figures of the group, who could always be found at the salons in which the group exhibited. His connections with Parisian art circles also ensured the reputation of Lorraine artists in the French capital. Nevertheless, the École de Nancy was often short of money, and formal artistic cooperation among its members slowly disintegrated during World War I.