Background. Low levels of physical activity (PA) in adolescents highlight the necessity for effective intervention. During adolescence, peer relationships can be a fundamental aspect of adopting and maintaining positive health behaviors. Aim. This review aims to determine peer-led strategies that showed promise to improve PA levels of adolescents. It will also identify patterns across these interventions, including training provided and the behavior change techniques (BCTs) employed. Method. Adhering to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, PubMed, PsychINFO, and Scopus were searched using key concepts of peer, PA and adolescent for articles that examined interventions that had a peer-led component and reported on at least one PA outcome in 12- to 19-year-olds. Following title and abstract screening of 1,509 studies, and full text review stage, 18 progressed to data synthesis. Methodological quality was assessed using an adapted scale. Results. Quality assessment identified 11 studies as high quality. Half of the included studies (n = 9) reported improved PA outcomes in the school setting. The most prominent behavioral change techniques were social support, information about health consequences, and demonstration of the behavior. Older adolescents leading younger peers and younger adolescents leading those of the same age showed potential. Seldom have older adolescents been targeted. Gender-specific interventions showed the most promise. Conclusion. Peer leadership requires careful planning and in the school setting can be a resourceful way of promoting adolescent PA.