Substance misuse, obesity, mental health conditions, type 1 diabetes, cancers, and cardiovascular and chronic respiratory diseases together account for 41% of disability-adjusted life years linked to noncommunicable diseases (NCDs) among children and adolescents worldwide. However, the evidence on risk factors and interventions for this age group is scarce. Here we searched four databases to generate an evidence gap map of existing interventions and research gaps for these risk factors and NCDs. We mapped 159 reviews with 2,611 primary studies; most (96.2%) were conducted in high-income countries, and only 100 studies (3.8%) were from low- and middle-income countries (LMICs). The efficacy of therapeutic interventions on biomarkers and adverse events for NCDs appears to be well evidenced. Interventions for mental health conditions appear to be moderately evidenced, while interventions for obesity and substance misuse appear to be moderate to very low evidenced. Priority areas for future research include evaluating digital health platforms to support primary NCD prevention and management, and evaluating the impact of policy changes on the prevalence of obesity and substance misuse. Our findings highlight the wide disparity of evidence between high-income countries and LMICs. There is an urgent need for increased, targeted financing to address the research gaps in LMICs.