The purpose of this study was to examine the relationships among trust in administrator, distributed leadership and a school academic optimism based on teachers' perceptions and to examine the mediator role of distributed leadership in the relationship between the levels of trust in administrator and the school academic optimism. The participants were a total of 540 teachers employed in elementary, middle and high schools located in the Kadikoy district of Istanbul. The data were gathered through the "Trust in Administrator Scale", the "Distributed Leadership Scale" and the "School academic optimism Scale". Arithmetic mean, the Pearson Product-Moment Correlation Coefficient, and regression analysis were used for data analysis. The results showed that trust in administrators predicted the distributed leadership and the school academic optimism, while distributed leadership also predicted the school academic optimism. Additionally, distributed leadership was found to have a partial mediator role in the relationship between trust in administrator and school academic optimism.