According to the literature pertaining to human resource development (HRD), a supervisor’s role in training programs has two major characteristics: support and communication. The ability of supervisors to play effective roles in training programs may increase employees’ job performance. More importantly, extant research in this field reveals that the effect of the supervisor’s role in training programs on job performance is indirectly affected by the motivation to learn. The nature of this relationship is less emphasized in training management literature. Therefore, this study was conducted to measure the effect of the supervisor’s role in training programs and the motivation to learn on job performance using 91 usable questionnaires gathered from employees who have worked in a state library in East Malaysia, Malaysia. The outcomes of stepwise regression analysis displayed that the inclusion of motivation to learn in the analysis had increased the effects of the two supervisor’s role elements of support and communication on job performance. This result demonstrates that the motivation to learn acts as a mediating variable in the training model of the organizational sample. The implications of this study to the theory and practice of training programs, methodological and conceptual limitations as well as future directions are elaborated.