This study investigates whether teachers’ organizational commitment mediates the relationship between their perception of principals’ transformational leadership and their organizational citizenship behavior (OCB). OCB refers to actions taken by teachers beyond their formal job duties toward students, colleagues, or the school. Such behaviors are particularly significant in the educational context, where budgeting is limited and job expectations are often vaguely defined. OCB has been linked to a variety of positive outcomes, including improved student behavior and higher teacher job satisfaction, and is shaped by professional and organizational conditions.

Drawing on psychological contract theory, which suggests the fulfillment of an implicit contract between employee and employer based on mutual expectations leads to organizational commitment which in turn promote positive employee's outcome, the study posits that principals’ transformational leadership helps meet teachers’ expectations, thereby strengthening their emotional connection to the school, manifested through OCB.

A total of 1,651 Israeli teachers participated in an online survey that included measures of principals’ transformational leadership, teachers’ organizational commitment, OCB, and demographic characteristics. Analysis using SPSS PROCESS Model 4 revealed that teachers’ organizational commitment fully mediates the relationship between principals’ transformational leadership and teachers’ OCB, explaining 24% of its variance.

The findings indicate full mediation: transformational leadership was significantly associated with teachers’ organizational commitment (β = .46, p < .001), which in turn significantly predicted teachers’ OCB (β = .30, p < .001). The direct path between leadership and OCB was not significant when controlling for commitment, thereby supporting full mediation.

This study emphasizes the importance of transformational leadership in fostering teachers’ OCB. Utilizing leadership as a strategic tool to promote school effectiveness proves to be highly efficient, as the principal’s behavior influences the entire organization without requiring large-scale training, prolonged implementation processes, or significant financial investment in professional development. Furthermore, developing leadership skills in principals has a longer-term impact on a broader group of personnel, in contrast to investing in individual teachers or coordinators, who may eventually change roles or leave the organization.

In addition, focusing on transformational leadership highlights its unique nature. It is described as a leadership style that enhances effectiveness of followers by nurturing the school staff through building a shared vision and connecting organizational goals with their personal and ethical values. As changes in schools are primarily enacted through staff, and principals often operate behind the scenes without direct influence on students, strong transformational leadership that empowers staff members is particularly vital in educational settings.

While this model has been examined in various international contexts, this is the first time it has been empirically tested in the Israeli education system. The findings underscore the importance of adopting transformational leadership practices in Israeli schools, with the potential to enhance school functioning and promote sustainable teacher engagement.

Keywords: Transformational Leadership, Organizational Commitment, Organizational Citizenship Behavior, Teachers, Principals, Psychological Contract, School Effectiveness.