<p>In recent years, public policies focused on child and adolescent protection have recognized the importance of promoting their participation to positively impact their well-being. Using a mediation framework, we analyzed the effect of participation on the subjective well-being of children and adolescents who have experienced rights violations, as well as the mediating role of eudaimonic well-being in this relationship. A total of 471 children and adolescents enrolled in Chilean outpatient rights protection programs participated. An adapted and validated version of the ISCWeB questionnaire was used to assess variables such as participation in daily life, eudaimonic well-being (CW-PSWBS), and subjective well-being, across both the cognitive (SLSS, OLS) and affective (Russell) dimensions. For the analysis, correlation analysis, mediation analysis using Hayes’ PROCESS macro, and bootstrap analysis were performed. A significant mediating effect of eudaimonic well-being was found between participation, life satisfaction, and positive affect. For negative affect, full mediation was observed: participation reduced negative emotions exclusively by strengthening eudaimonic resources, with no residual direct pathway. These findings highlight the importance of fostering participation and eudaimonic well-being as protective strategies for children and adolescents in vulnerable contexts.</p>