Critical Analysis of Principal Leadership Styles in Order to Improve Teacher Performance in the Sudirman Cluster, Punggelan District, Banjarnegara. Thesis, Graduate Program, University of Muhammadiyah Purwokerto, 2021. The Principal in the Education Unit is the leader. He has two positions, namely as a formal leader and school administrator. In carrying out their duties, each school principal uses different strategies and methods according to his character, which is known as the type and style of leadership. The style or manner of a principal in his capacity as a leader will determine the success of improving the performance of teachers under his leadership. The aims of this study were to: 1) To find out the implementation of the principal's leadership style in order to improve the performance of teachers in the Sudirman Cluster. 2) To find out the obstacles to the implementation of the principal's leadership style in order to improve the teacher's performance in the Sudirman Cluster. 3) To find out the efforts overcome obstacles in implementing the principal's leadership style in order to improve teacher performance in the Sudirman group. The data collection techniques used in this thesis are observation, interviews and documentation. The data analysis technique used is data collection, data reduction. The results showed that the leadership style of the elementary school principal in the Gugus Jenderal Sudirman, Punggelan District, Banjarnegara, was democratic, this could be seen from the principal's role as an educator. It is recommended that the principal can apply a better or varied leadership style so that the desired goals can be achieved properly and optimally.