Background: Researchers have consistently documented the relationship between optimism and benefit finding; however, there is a dearth of research on the psychological mechanisms mediating their association. Aim: This cross-sectional study sought to elucidate the mediating role of positive reappraisal and social support in the optimism-benefit finding relationship in parents caring for children with developmental disabilities by testing a parallel multiple mediation model. Method: One hundred and forty-six parents caring for children with developmental disabilities completed an online survey assessing optimism, positive reappraisal, social support and benefit finding. Results: Optimism was not directly related to benefit finding but rather influenced it indirectly through positive reappraisal and social support. Specifically, higher levels of optimism predicted greater positive reappraisal and social support, which in turn led to greater benefit finding in parents. Conclusion: These results underscore the importance of targeting parents’ perceptions of benefits through both positive reappraisal and social support in order to help them cope with the demands of the caregiving context.