This cross-sectional study explores the role of grit and positive psychological resources (emotion regulation and optimism) and the processes between them that explain depressive symptoms. Understanding how grit and positive psychological resources can work independently and through each other to influence depressive symptoms can prove beneficial for higher education institutions in understanding why gritty students are less depressed, and the supported paths can be used to design mental health programs that enhance the appropriate psychological resources, which may assist with preventing students from the risk of depression. A sample of 165 participants (67.7% females and 88.4% undergraduates), with a mean age of 20.52 years (range 18-39), completed a structured self-reporting questionnaire. A serial multiple mediator model was analyzed to explain sequential relations among emotion regulation and optimism and to investigate the direct and indirect effects in SPSS 30, Amos 30, and PROCESS macro program (Model 6; bootstrapping with 5,000 resamplings and 95% confidence interval). Results supported that grit, two types of emotion regulation (cognitive appraisal and expressive suppression), and optimism were significantly associated with depressive symptoms. Moreover, a serial mediation (β = -0.02, 95% CI [-0.059, -0.002]) was found among the variables: gritty students tended to report higher cognitive appraisal, which further increased their positive outlook towards life and the future, and subsequently weakened perceived depressive symptoms. The total effect of grit on depressive symptoms was significant, and the proposed model accounted for 35.4% of the explained variance in depressive symptoms. Practically, in order to reduce the risk of depression, researchers and educators can help students identify their achievable life goals and/or academic goals, incorporate strategies to primarily foster cognitive appraisal of the stressors or stressful events and of their emotional reactions to these stressors and events, and prompt positive expectations and hope for goal attainment and the future.