<p>Organizational citizenship behavior (OCB) plays a critical supporting role in promoting the holistic performance and sustained vitality of an organization. Transformational leadership (TL) has been reported to be positively correlated with OCB and other extra-role behaviors among employees. However, the mechanism by which principals’ TL impacts teachers’ OCB in the Chinese educational context has not been fully explored. The purpose of this study is to investigate both the relationship between principals’ TL and teachers’ OCB and the potential mediating role of clan culture and work alienation. A sample of 912 teachers from a northern city in China was invited to participate in the survey. Descriptive statistics and structural equation modeling (SEM) were employed to analyze the data. The findings demonstrated that the direct effect of principals’ TL on teachers’ OCB was not significant. Rather, clan culture and work alienation served as mediators both independently and sequentially, constituting a full chain mediation mechanism. These results underscore the importance of integrating TL, clan culture, and work alienation into efforts to foster teachers’ OCB and identify pathways by which such integration can be cultivated.</p>