AbstractTo address why the relationship between affective organizational commitment and job performance varies, we draw on the theorization of Meyer, Becker, and Vandenberghe to propose moderation of affective occupational commitment and transformational leadership, separately and interactively. Data collected from 398 employees and their supervisors supported our hypotheses. Specifically, affective organizational commitment was more strongly associated with job performance for employees with high occupational commitment, or when a supervisor's transformational leadership was high. Importantly, in a moderated mediation relationship, we found the effect of transformational leadership on the relationship between affective organizational commitment and job performance for employees with high occupational commitment was contrary to its effect on employees with low occupational commitment. Given the significant roles of both commitments as discussed in the present study, we offer suggestions on how to consider these factors during the assessment and selection of personnel and role assignment.