As teacher well-being is impacted by the leadership ability of school management, which helps establish trust and cooperation among the teaching faculty, it is an important subject of research. Therefore, this study aims to explore how the authentic leadership of school principals impacts (1) the teacher-school relationship (based on organizational trust, organizational identification, and organizational commitment), and (2) teachers' organizational citizenship behavior. In addition, mediating effects of the teacher-school relationship and organizational citizenship are investigated. For data collection, senior high/vocational school teachers in central Taiwan were recruited to participate in a self-reported questionnaire survey. Specifically, 783 valid responses were retrieved. The empirical findings are as follows. First, the principals' authentic leadership had a direct effect on teachers' organizational trust, organizational identification, organizational commitment, and organizational citizenship behavior. Second, organizational identification and organizational commitment directly affected organizational citizenship behavior. Third, organizational trust, organizational commitment, and organizational citizenship behavior directly affected teachers' well-being. Finally, organizational trust, organizational commitment, and organizational identification had a mediating effect on the relationship between authentic leadership, organizational citizenship behavior, and teacher well-being. The academic and practical implications, as well as contributions of the study, are discussed, and suggestions for future research and management are proposed.