Currently, educational institutions are going through significant challenges across all EU countries. Therefore, school principals need an appropriate leadership style to support teachers through these obstacles, supporting them in their professional development and promoting their satisfaction. This study explores the relationship between transformational leadership and teachers' job satisfaction through professional development attitudes. Moreover, we investigate the moderating role of learning program management, namely the leader's strategies and practices that integrate teacher development within a school-wide learning system. A sample of N = 1,091 tenured teachers answered our paper-and-pencil questionnaire. Study hypotheses were tested using structural equation modelling. The results of our study confirmed mediating and moderating hypotheses, emphasising the importance of supporting teachers' professional development to promote their satisfaction and foster their positive attitudes towards their development. Furthermore, we underline the importance of investing in school principals' leadership skills, which can be directly associated with teachers' personal and professional outcomes.