Mental health disorders among primary school children remain a crucial issue. Early health promotion interventions can positively affect and prevent the onset of mental disorders. Promising digital mental health methods have been implemented for adolescents and youths with scarce evidence among younger ages. Therefore, the aim of the current systematic review was to identify health promotion interventions on mental health and wellbeing, with the use of digital methods, delivered in primary school settings. Six digital interventions have been identified, three of which were targeting teachers and the others students. Regardless of the limited number of studies, the effectiveness of the web-based interventions upon teachers’ knowledge and attitudes and the positive impact on children’s behavioral improvements has been documented. The lack of adequate evidence highlights the need for further research in the field. The current review provides information for professionals working in primary schools useful for the design and implementation of effective mental health and wellbeing interventions.