Objective <p>This study aimed to examine how physical self-esteem and psychological resilience influence adolescents’ sports participation, with a focus on the mediating roles of exercise motivation and social support. The goal was to clarify the interaction between individual psychological resources and contextual social factors in shaping youth physical activity.</p> Method <p>A total of 2,588 adolescents from 15 provinces in China completed validated questionnaires assessing physical self-esteem, psychological resilience, exercise motivation, social support, and sports participation. Structural equation modeling (SEM) was used to test direct and indirect pathways. Multi-group analyses were conducted to examine model invariance across gender, grade level, and residential background.</p> Results <p>Physical self-esteem and psychological resilience positively predicted sports participation both directly and indirectly. Exercise motivation and social support served as significant mediators, with a sequential pathway from psychological traits to behavioral outcomes via motivational and social mechanisms. Structural invariance was supported across all demographic subgroups, indicating the model’s robustness and generalizability.</p> Conclusion <p>The findings underscore the dual importance of internal self-perception and external support systems in promoting adolescent engagement in sports. By elucidating a chain mediation process, this study contributes to a more nuanced understanding of youth physical activity and offers practical implications for developing targeted interventions in school, family, and community settings.</p>