Abstract Despite the growing focus on adolescent loneliness and loneliness interventions, our understanding of successful approaches for tackling loneliness in childhood and adolescence remains limited. While recent reviews have made advances in exploring loneliness interventions for this age group, our understanding of successful approaches remains limited. Key knowledge gaps persist, particularly concerning potential moderators - specifically, the characteristics that may determine the effectiveness of an intervention is sparse, leaving a significant gap in our understanding of which interventions are most effective and for whom. This presentation aims to fill this gap by presenting the findings of a systematic review and meta-analysis on interventions to reduce loneliness in children and adolescents. The presentation will provide a brief overview of the methodology employed and provide insights into the characteristics of the interventions reviewed, including an assessment of their overall effectiveness in alleviating loneliness. The primary focus, however, will be on presenting findings regarding the effectiveness of interventions across different participant groups, including variations based on socio-economic status, age group, pre-existing mental and physical health conditions, as well as baseline levels of loneliness. Additionally, the presentation will explore the impact of different intervention strategies on the effectiveness of loneliness interventions for children and adolescents. Lastly, the presentation will offer reflections on avenues for future research and practice based on the findings.