In 1976, Mrs. Odette Cutullic, then a United Nations Civil Servant, was the initiator and President of the Crèche des Nations for staff of international organizations in Geneva. It was the first daycare centre to apply Montessori pedagogy for children from 2 months to 6 years old and the largest (120 children). The Crèche was taken over by the City of Geneva in 1994. Mrs. Cutullic is a founding member of the Swiss Montessori Association, of which she was the President for eight years.

Over the years, faced with the growing demand from parents for Montessori education up to Elementary level, Mrs. Cutullic, with the support of Mrs. Denise Baechler and Mr. Pierre Marconi (retired UN Civil Servant), considered the creation of a school for children from 3 to 9 years old. Two small villas were fitted out for this purpose, Rue de Lausanne in Geneva.

The Ecole des Nations Foundation was established in 1989. It is managed by a Foundation Board which is responsible for the long-term strategy and administration of the School. The day-to-day management of the School is carried out by a manager, appointed by the Foundation Board.

In 2007, faced by the obligation to leave the premises, and repeated requests from parents for education covering the entire Elementary school curriculum, a possibility of expansion arose with nice spacious premises which previously housed another school. This move made it possible to offer education up to 12 years old and 91 students were able to integrate this new space.