Despite the attempts by lawmakers to legislate a closing of the achievement gap, persistent gaps in performance for students based on ethnicity, race, economic level, disability, and first language persist throughout public schools in the United States. Occasionally, a principal will receive attention for raising the performance of minoritized groups in their school. However, while admired, the principal's efforts are not easily replicated. Furthermore, principal development programs fail to produce building leaders that can reliably achieve the change marginalized communities need. There have been numerous studies that have shown that principals impact the academic performance of their students. For the last several decades, principals have been told to focus on instructional leadership, to be transformative leaders, and to distribute leadership responsibilities to teacher leaders. Yet, student performance has largely remained unchanged. Because of the lack of success and the evolution of schools' societal role, principals are being called to be systems thinkers. In this mixed-method study, a review of the research related to systems thinking by school leaders is paired with an evaluation of student academic performance. The study is done on public schools along the I-5 corridor in western Washington. Building leaders were asked to evaluate their leadership on the Principal Systems Thinking Scale (PSTS). Their scores were then assessed against their students' performance on the Smarter Balanced Assessment (SBA) in English Language Arts and math. The PSTS survey also included open-ended questions where principals were asked to describe their leadership. The study found inconclusive results on the impact of the level of a principal's self-reported systems thinking and the academic performance of their students. Additionally, results were inconclusive on the impact of systems thinking on closing the academic outcome gap. However, the study highlighted that principals have a limited understanding of systems thinking. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]