Purpose: Research investigating the impact of school leadership on teachers' emotions and practices has mostly focused on the leadership behaviors of school principals, thus ignoring the potential leadership qualities of other school members, especially teachers. The current study aimed to bridge this gap by providing further insight into the link between teacher leadership and teacher outcomes in Egyptian schools. Specifically, the study examined the mediating role of collective teacher efficacy in the relationship between teacher leadership and teacher commitment. Design/methodology/approach: The study employed structural equation modeling and bootstrapping to analyze survey data collected from 497 teachers in primary and middle schools in Damietta city, Egypt. Findings: The results supported our proposition that teachers' leadership practices have more indirect than direct effects on teacher commitment through collective teacher efficacy. That is, teacher leadership practices positively affect teachers' efficacy beliefs, which, in turn, increase their sense of commitment to school. Originality/value: The study adds a new aspect to the literature by investigating the potential role of teacher leadership in promoting positive teacher attitudes that can have a positive impact on student learning. This is significant given the growing emphasis that educational systems place on enhancing school effectiveness. Specifically, understanding the factors that contribute to teacher commitment can inform strategies for retaining effective teachers and improving the overall quality of the teaching workforce. Additionally, since most of the empirical research on teacher leadership has been produced in Western contexts, it is important to enrich the field with studies conducted in other societies, especially in the Arab region.