Background The fossil fuel industry’s practices and products create wide‑ranging harms to human health, with disproportionate impacts on communities already affected by structural disadvantage. Young people, particularly adolescents, are among those most affected by these harms, yet they are often excluded from health and climate decision-making. At the same time, youth-led initiatives to counter the fossil fuel industry’s practices and products are increasing globally. Despite this momentum, little is known about what interventions involving adolescents exist, how they work, and under what circumstances they may reduce health inequities driven by the fossil fuel industry. This study protocol aims to address this gap by conducting a realist review to explore how interventions involving adolescents can counter industry practices and products. It takes a structural racism lens to examine how inequities shape both exposure to harm and opportunities for participation. The review seeks to identify relevant interventions, understand the mechanisms through which they produce change, and examine the contexts that enable or hinder their effectiveness. Methods The study follows established realist review standards and draws on diverse sources of evidence, including published research and grey literature. Adolescents and a multidisciplinary expert steering group have contributed to shaping the review questions and will continue to be involved throughout the process. The review will generate explanations about how interventions work by developing context–mechanism–outcome configurations. These explanations will be refined through iterative synthesis and engagement with advisory groups. Discussion The review is expected to produce a set of theories illustrating how adolescents’ participation can influence action against the fossil fuel industry to help reduce health inequities. The findings will inform public health practitioners, policymakers, organisations working with adolescents, and researchers seeking to design, adapt, or scale interventions that amplify adolescents’ role in addressing the fossil fuel industry’s health harms.