<p>This study examined the relationships among gratitude, positive reappraisal, peace of mind, and psychological well-being, with a focus on their roles in being associated with mental health among Chinese college students. A cross-sectional design was employed, with 336 undergraduate students from various disciplines recruited through convenience sampling from four universities in mainland China. Participants completed validated self-reported measures of gratitude (GQ-6), positive reappraisal (CERQ), peace of mind (PoMS), psychological well-being (SPWB), and perceived academic pressure. Confirmatory factor analyses supported the construct validity of the scales, and structural equation modeling (SEM) revealed significant direct effects of gratitude, positive reappraisal, and peace of mind on psychological well-being. Additionally, peace of mind was found to mediate the relationships between gratitude, positive reappraisal, and well-being, suggesting that emotional stability and inner tranquility are important pathways to enhanced mental health. Clinically, these findings underscore the potential for integrating gratitude and positive reappraisal into therapeutic interventions to cultivate peace of mind and support mental health outcomes. Such interventions could be particularly valuable for students navigating high-pressure academic environments.</p>