Adolescence represents a critical developmental transition characterised by rapid neurobiological changes, identity formation, and heightened susceptibility to psychological distress. This research paper examines the impact of organised sports participation on three interrelated dimensions of adolescent development: self-esteem, social competence, and emotional well-being. Guided by Self-Determination Theory and Positive Youth Development frameworks, the study analyses the psychosocial mechanisms through which athletic engagement influences physical self-efficacy, peer relationship quality, and affective regulation. Utilising an 8-week pre-test and post-test experimental design with control (n = 50) and intervention (n = 50) cohorts (N = 100), quantitative assessments were conducted using standardised evaluation scales. The findings indicate that structured sports environments significantly enhance self-esteem (p < .001), social competence (p < .001), and emotional well-being (p < .001) compared to standard physical education controls. However, these psychological benefits are moderated by environmental factors, including coaching styles, parental pressure, and the motivational climate established within the athletic context. The paper concludes with strategic recommendations for educators and policy makers to optimize youth sports programs for positive adolescent health.