The present study aims to examine whether self-efficacy mediates the relationship between optimism, dimensions of psychological well-being, and resilience among Iranian students. The participants in this study included 251 Iranian students from Universiti Putra Malaysia (UPM). Structural equation modeling using AMOS 20.0 was used to analyze the data. The results indicated that there were significant relationships between optimism, dimensions of psychological well-being, and resilience among Iranian students of UPM. The study findings presented that self-efficacy mediated the relationship between dimensions of psychological well-being (environmental mastery, autonomy, self-acceptance, positive relations with others, personal growth, and purpose in life) and resilience among Iranian students of UPM. Furthermore, self-efficacy was not observed to mediate the influence of optimism on resilience among Iranian students of UPM. The study’s findings help to understand the interrelationship between self-efficacy, various dimensions of psychological well-being, and resilience. Consequently, counselors, psychologists, and instructors can develop and plan valuable strategies to enhance students’ psychological factors.