The aim of this study is to examine the relationship between entrepreneurial school leadership and teacher entrepreneurship based on teacher perceptions and to reveal whether teachers' perceived positive psychological capital plays a mediating role in this relationship. The participants of the study consisted of 1200 teachers working in public schools in Pendik district of Istanbul in the 2020-2021 academic year. The data of this quantitative study, in which structural equation modeling and mediation tests were used, were obtained using the Entrepreneurial Leadership Scale, Entrepreneurial Teacher Behaviors Scale and Positive Psychological Capital Scale. The results obtained from the research show that school leaders exhibit entrepreneurial leadership behaviors above the average in management processes, and that these entrepreneurial behaviors exhibited by school leaders significantly predict teacher entrepreneurship and teachers' perceptions of positive psychological capital in a positive direction. Furthermore, it was found that teachers' perceived positive psychological capital played a mediating role in the relationship between entrepreneurial leadership and teacher entrepreneurship. The model created in this context explains about 55% of the change in teacher entrepreneurship. In line with the evidence obtained from the research, it is recommended to organize awareness and development trainings for school leaders and teachers on entrepreneurial leadership, which is considered as a new leadership approach, teacher entrepreneurship and positive psychological capital, and to conduct studies on entrepreneurial leadership and different variables and mediators.