BackgroundInterventions to promote mental health in paediatrics need to be effective, especially in crisis contexts. This systematic review proposes to compile and analyse the findings of nonpharmacological interventions conducted in samples of children and adolescents during the COVID‐19 pandemic, focusing on mental health.MethodsThe research was carried out in PsycINFO, PubMed and Web of Science databases for empirical studies, including interventions in which measures of outcome variables were collected at least twice (pre and post). The studies' samples were children and adolescents up to 19 years old, and interventions were developed throughout the COVID‐19 pandemic. After eligibility analyses, 16 studies were included in this review.ResultsStudies used different theoretical approaches, focusing on the promotion, prevention and treatment of mental health in specific contexts. Some were delivered online, in‐person or in hybrid formats. Particularly, depression, the most frequently assessed outcome, demonstrated more favourable results within the interventions than other evaluated outcomes. However, due to the considerable risk of bias, the qualitative analysis of the results of many included studies should be performed with caution.ConclusionsMost of the interventions necessitate further validation, highlighting the ongoing need for research in this area. However, the emergence of interventions during crises, such as the COVID‐19 pandemic, provides an opportunity to expand evidence‐based mental health practices, paving the way for their application in other crisis situations. Given that mental health prevention and promotion practices can be integrated into the roles of all healthcare providers, possessing insight into the most suitable evidence‐based interventions can elevate the quality of care delivered.