Limited but increasing research has noted that middle leaders (MLs) play a crucial role in structuring a supportive working environment to help entrepreneurial teachers transform educational innovation into practice. This study aims to increase understanding of the extent to which MLs with different levels of experience influence teacher entrepreneurial behaviour (TEB). The study employs the three dimensions of the 'person-environment fit model,' namely, person-organisation fit, person-group fit, and person-job fit, as a theoretical lens to examine the relationships among MLs, working environment, and TEB. Findings revealed that the more years of experience MLs have in post, the more influence they have in promoting TEB; however, they have limited influence over shaping the working environment, especially the person-organisation environment. Furthermore, the mediating effect of the person-environment fit model was complex because teacher entrepreneurial behaviour was perceived to be a result of the synergy between the person-group and person-job environment. The findings advance knowledge about middle-leadership and teacher-entrepreneurial behaviour across the three dimensions of the person-environment fit model. They also highlight the importance of MLs' leading experience for TEB and further enrich the understanding of how MLs struggle to support TEB in a hierarchical working environment.