In research, participatory approaches involve engaging in the research with people and empower co-researchers to have a voice. The aim of this review was to synthesize the methods and approaches used to enable children, adolescents, and families to be involved in a participatory approach in research conducted to inform development of health resources and interventions aimed at children and adolescents. Key databases were searched systematically using key word and subject heading searches and included studies were appraised for both methodological quality and sufficiency of reporting of their participatory approach. Findings were synthesized using a critical narrative approach. Among 26 eligible studies, commonly reported participatory approaches involved community-based participatory research, codesign, participatory design, coproduction, and user-centred design. A need was identified to involve co-researchers more in the later stages of participatory approaches. Most studies were of low to moderate methodological quality. A wide variety of methods and activities were used in the studies to enable children to participate in the research, but few studies provided sufficient evidence of their participatory approach. This review concludes that reporting of participatory approaches might benefit from the guidelines that acknowledge the dual nature of participatory approaches as both a research method and an approach that enables action and change.