AbstractThe psychosocial health of children and adolescents has been particularly affected by the COVID-19 pandemic. Containment measures have restricted social development, education and recreational activities, may have increased family conflicts and, in many cases, led to feelings of loneliness, sleep disturbances, symptoms of anxiety and depression. We conducted a systematic review to identify interventions that seek to ameliorate these detrimental effects of the COVID-19 pandemic and to build resilience in children and adolescents. Literature searches were conducted in the databases MEDLINE, EMBASE, PsycINFO, CENTRAL, WHO COVID-19 Global literature on coronavirus disease and Cochrane COVID-19 Study Register (up to 30 June 2022). The searches retrieved 9557 records of which we included 13 randomized-controlled trials (RCTs) for evidence synthesis. Included studies predominantly implemented online group sessions for school-aged children with either a psychological component, a physical activity component, or a combination of both. A meta-analysis of seven studies on anxiety and five on depressive symptoms provided evidence for a positive effect of interventions by reducing anxiety (Standardized Mean Difference (SMD) (95% CI): − 0.33 (− 0.59; − 0.06)) and depressive symptoms (SMD (95% CI): − 0.26 (− 0.36; − 0.16)) compared to the control interventions. Studies also showed improvements in positive mental health outcomes, such as resilience (n = 2) and mental and psychological wellbeing (n = 2). Exploratory subgroup analyses suggested a greater effectiveness of interventions that (i) are of higher frequency and duration, (ii) enable personal interaction (face-to-face or virtually), and (iii) include a physical activity component. Almost all studies were judged to be at high risk of bias and showed considerable heterogeneity. Further research may focus on the contribution of different intervention components or distinct subgroups and settings, and should examine children and adolescents over longer follow-up periods.