The purpose of this study was to examine the relationship between principal leadership styles and the academic achievement of students with disabilities. Participants were North Carolina elementary and middle school principals and teachers. The researcher examined what leadership styles (transformational, transactional, or passive-avoidant) are employed by principals in schools that have demonstrated high academic growth from their students with disabilities. The Multifactor Leadership Questionnaire (MLQ-5X) was administered to special education teachers to rate their principal's leadership style. In addition, the researcher conducted semi-structured interviews with principals to determine the leadership practices they are implementing to promote student success. Descriptive statistics were implemented to identify the dominant leadership styles and demographic trends. Correlation analysis was conducted to determine the relationship and significance between the principals' leadership style and other independent variables in association with academic achievement for students with disabilities. Lastly, thematic analysis and constant comparison methods were employed to analyze principal interview data. The principals in this study led through a more transformational style, ranking high in inspirational motivation and idealized influence. In addition, they focused on collaboration, communication, and high expectations. A significant relationship was found between student achievement and principals who ranked low in laissez-faire leadership. This study adds to the existing body of leadership and student achievement literature and provides data to the current gap in research in regards to students with disabilities. Additionally, this study supplies policymakers and practitioners with successful leadership practices that are employed by principals to promote academic achievement for students with disabilities. [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://www.proquest.com/en-US/products/dissertations/individuals.shtml.]