<p>Positive childhood experiences (PCEs) represent a promising yet understudied pathway to resilience and adaptive functioning in adolescence. Self-regulation, a critical skill for emotional and behavioral control, may be cultivated through PCEs by fostering social connectedness and dispositional hope—factors theorized to promote future-oriented coping. This study aimed to examine the mediating role of hope and social connectedness on the relationship between PCEs and self-regulation success and failure in adolescence. A cross-sectional survey of 343 adolescents (aged 15–17) enrolled in high schools from Türkiye, assessed PCEs, self-regulation, social connectedness, and dispositional hope. Demographic variables, including gender, grade level, perceived socio-economic status, and academic achievement were controlled for in analyses. Serial mediation analyses using Hayes’s PROCESS macro (Model 6, 5,000 bootstraps) revealed that PCEs significantly predicted self-regulation success through hope, but not through social connectedness. The total indirect effect was significant (<i>b</i> = 0.288, 95% CI [0.207, 0.376]), with hope emerging as a strong predictor of self-regulation success (<i>b</i> = 0.462, <i>p</i> &lt; .001), whereas social connectedness was not significant (<i>b</i> = 0.017, <i>p</i> = .647). The model explained 43% of variance in self-regulation success. In contrast, neither hope (<i>b</i> = 0.055, <i>p</i> = .096) nor social connectedness (<i>b</i> = 0.039, <i>p</i> = .250) mediated the relationship between PCEs and self-regulation failure, with the model explaining only 8.4% of variance. These findings highlight hope as the primary mechanism through which PCEs enhance adolescent self-regulatory capacity. Interventions targeting hope development may effectively strengthen the link between positive experiences and self-regulation success in adolescents.</p>