In order to increase the efficiency and productivity of employees and organizations industrial and organizational psychologists have identified and examined the important psychological structures affecting the effectiveness of organizations and to achieve this goal the variables of job enthusiasm, authentic leadership and scientific optimism have always been considered.The purpose of this study is to investigate the mediator role of the scientific optimism in relationship between authentic leadership andteachers' job engagement. The study is an applied descriptive correlational one in which he statistical population consisted of all English language teachers in the city of Sanandaj from among which 190 individuals were selected as samples based on Morgan Table and using a random stratified method. They responded to three questionnaires of authentic leadership, academic optimism, and job engagement. The results were analyzed using structural equation modeling method. Findings indicated that that authentic leadership has a direct effect on scientific optimism, scientific optimism has a direct effect on job enthusiasm, and authentic leadership has a direct effect on scientific optimism. furthermore, authenticleadership through scientific optimism has an indirect effect on job engagement and the hypothetical model of the research showed a good fit. Therefore, it can be said that authentic leadership and academic optimism are important variables that are closely related to job engagement in teachers.
