Mental health concerns are increasingly prevalent among postgraduate students, who face academic, social, and career pressures. Although research on student mental health is expanding, less is known about the psychological resources that support well-being in postgraduate learners. Meaning in life has been identified as a key psychological resource that helps individuals interpret challenges and maintain coherence and well-being, and recent research highlights the contribution of self-transcendent traits such as gratitude, forgiveness, and spirituality in fostering meaning in life. However, empirical evidence on these interrelationships remains limited. This study involves 1527 Pakistani postgraduate students (M = 795; mean age = 24.89 years) recruited through multistage random sampling from ten public universities in Punjab. Participants completed the Gratitude Questionnaire, Heartland Forgiveness Scale, Spirituality Scale, Meaning in Life Questionnaire, and Mental Health Inventory (assessing psychological well-being and psychological distress). Correlation analyses showed that gratitude, forgiveness, and spirituality were positively associated with psychological well-being and negatively associated with psychological distress. Structural equation modeling (SEM) further indicated that these traits predicted mental health both directly and indirectly, with meaning in life serving as significant partial mediator. Overall, the findings highlight the central role of meaning in life in linking self-transcendent traits to mental health among postgraduate students and suggest important implications for culturally sensitive, university-based mental health initiatives.