This study examines the mediating role of teachers' perceived administrator support in the relationship between principals' social justice leadership behaviors and teachers' trust in principals. The sample of the study, which was designed in the relational survey model, consists of 903 teachers working in public schools in a metropolitan city in Southeast Türkiye. In the context of the research model, the SPSS Process Macro (Model-4) application developed by Hayes (2018) was used to determine the mediation effect. Because of the analysis of the research data, it was determined that the social justice leadership behaviors exhibited by school principals predicted both teachers' trust in the principal and teachers' perceived administrator support positively and statistically significantly. On the other hand, it was concluded that perceived administrator support plays a mediating role in the relationship between principals' social justice leadership behaviors and teachers' trust in principals. In this context, it can be staded that if school administrators' social justice leadership behaviors increase, both the administrator support perceived by teachers and their trust in the principal will increase.