Previous reviews have summarized the results of interventions aimed at reducing sedentary behavior among youth, but evidence-based best practice is needed. This systematic review aimed to synthesize evidence to determine which intervention strategies/characteristics are powerful in reducing sedentary behavior among children and adolescents. Eight electronic databases were used. The eligibility criteria were systematic reviews (published in English, Spanish and Portuguese) that analyzed clinical trials to reduce sedentary behavior in young people (age ≤ 18 years). Twenty-nine studies were included. Eleven out of 29 previous reviews had low methodological quality. Almost all reviews reported that interventions were effective in reducing sedentary behavior; however, most of them (26 reviews) had limited evidence due to the inconsistency of results, low methodological quality and/or small sample size. School have been the most used context and strategies that involve family, used control devices, educational materials and standing desks show effectiveness. However, other answers are still unclear, such as the effectiveness of interventions for different types of sedentary behaviors (e.g., TV time), the necessary length for intervention, and the effectiveness of mediators. Thus, future and high-quality studies should consider addressing such questions in order to support evidence-based interventions to reduce sedentary behavior.