SummaryMany interventions are implemented in the public health context to overcome social inequalities of weight status in adolescents, but their effectiveness is challenged. This study aimed to examine the effectiveness of these interventions with a systematic review and meta‐analysis. We systematically searched for reports of randomized control trials and quasi‐experimental studies aiming to reduce social inequalities of weight status in adolescents in five electronic databases. The primary outcomes were social inequalities in weight‐related outcomes (body mass index [BMI], BMI z score, waist circumference, percent body fat, prevalence of overweight/obesity). Interventions were effective when they reduced social inequalities in at least one weight‐related outcome. Meta‐analyses involved using random‐effects models. The review included 38 publications (33 studies) with interventions mostly targeting disadvantaged adolescents (n = 29 studies), showing effectiveness in half of the studies (n = 19/33, 57.6%). The meta‐analysis (27 studies) revealed that targeted interventions significantly reduced BMI z score (β = −0.04 [95% CI −0.08, −0.01]), BMI (β = −0.32 [−0.47, −0.18]), and waist circumference (β = −0.84 [−1.48, −0.21]) but not percent body fat (β = −0.27 [−0.71, 0.17]) or prevalence of overweight/obesity (odds ratio = 1.06 [0.85, 1.31]). This review shows moderate effectiveness of interventions targeting disadvantaged adolescents to reduce social inequalities of weight status. High‐quality research with better implementation to reach their full potential is required to strengthen their effectiveness.