Abstract Background Adolescent obesity has been reported to have deleterious consequences but is considered a promising modifiable risk factor. We aimed to investigate the optimal intervention for obese and overweight children and adolescents. Methods We searched the Medline (PubMed, 1946–December 2020), PsycINFO (Ovid, 1927–December 2020), Cochrane library (1966–December 2020), Web of Science (1900–December 2020), Embase (1974–December 2020), CINAHL (1937–December 2020), Chinese Biomedical Literature (1978–December 2020), and ClinicalTrials.gov (December 2020) databases. We included randomized controlled trials (RCTs) reporting the association between various interventions and obese/overweight children and adolescents. The quality of the included studies was judged by two independent reviewers using the Cochrane Collaboration Risk of Bias Tool. A Bayesian network meta-analysis was conducted to summarize the comparative effectiveness of interventions based on several outcomes. Results We included 118 RCTs comprising 71,064 participants in our analyses. Based on the outcome of the body mass index (BMI), face-to-face physical activity (FTF PA) combined with dietary intervention (DI) (mean difference [MD] = − 0.98; 95% credible interval [CrI] − 1.19, − 0.77), FTF multi-lifestyle intervention (MLI) (MD = − 0.95; 95% CrI − 1.14, − 0.75), and mobile health (MH)-delivered MLI (MD = − 0.87; 95% CrI − 1.63, − 0.09) showed significant benefits over the named control group (NCG). For the outcome of BMI z-score, FTF PA+DI (MD = − 0.10; 95% CrI − 0.15, − 0.04) and MH-delivered PA+DI (MD = − 0.09; 95% CrI − 0.14, − 0.04) were more effective than the NCG. Sensitivity analyses revealed similar findings after exclusion of studies with < 12-month and 24-month outcome assessments for the intervention, which indicated the results were stable. Conclusions Based on limited quality evidence and limited direct evidence, our preliminary findings showed that FTF-PA+DI, FTF-MLI, and MH-delivered MLI improved the health-related parameters in obese adolescents, in comparison with NCG. Owing to the absence of strong, direct evidence of a significant difference between the various interventions for the four outcomes, we can only cautiously suggest that FTF-PA+DI is likely the most effective intervention.