Infectious diseases continue to cause numerous deaths worldwide, including among young people. This article aims to provide an overview of the scientific evidence regarding validated or promising interventions for the prevention of gastrointestinal and respiratory diseases in young people through hand hygiene promoted in school settings. This review was conducted using a specific methodology for selecting and analyzing the scientific literature and classifying the identified interventions. About ten interventions were thus identified for their beneficial impact through the promotion of handwashing in schools. Most interventions are carried out in elementary schools; however, some begin as early as preschool or even daycare, or are conducted later, at the university level. Almost all are regular interventions led by teachers, peers, and/or external professionals. Although the hygiene products used vary—regular and/or antibacterial soap, hand sanitizer, alcohol-free solution—they do not differ in terms of effectiveness. Knowledge of these interventions, which have been validated or shown promise at the international level, should help inform discussions about practices developed in France.[author’s abstract]