Source Article in French:
Plus de téléphones portables dans les écoles et collèges à la rentrée 2018 », annonce Jean-Michel Blanquer
https://www.lemonde.fr/education/article/2017/12/10/plus-de-telephones-portables-dans-les-ecoles-et-colleges-a-la-rentree-2018-annonce-le-ministre-de-l-education-nationale_5227485_1473685.html

2017: Cell Phones are fully banned – in hallways, lunchroom and playgrounds- in schools through 14-15 years old (elementary and middle).

● Mobile phones will be fully banned announced the Minister of National Education Jean-Michel Blanquer according to a news article published in Le Monde​. The measure was confirmed by the Minister of Education. While France previously banned cell phones in classrooms, this policy includes all locations in the school and is considered a “full ban”.
Source