The educational literature has a long history of studies focusing on relationships among a variety of variables such as leadership practices, teachers' behaviors, and students' educational outcomes. The behavior of leaders has been identified as a characteristic that directly influences an employee's creative behaviors and organizational innovation. Fostering creativity in education is intended to address many concerns, such as dealing with ambiguous problems, coping with the fast-changing world, and facing an uncertain future (Parkhurst, 1999). Although creativity is essential in education, teachers have not received adequate support from school principals to enhance creativity. Transformational leadership is one of the most prominent leadership concepts. It is associated with creating and developing the capacity and the conditions of organizations, such as for organizational culture, organizational learning, knowledge management, and effective learning environment (Leithwood & Jantzi, (2000); Noruzy et al. (2013). Studies have shown that the leadership style of the school heads strongly influence several elements of the school environment, including teacher and staff attitudes, student learning, and academic achievement. This study sought to address the problem that current literature had inadequately investigated on the relationship between transformational leadership and school creativity. It also aimed to examine the relationship between teacher leadership and students' academic achievement. The purpose of this quantitative correlational study was to investigate if there was any relationship between principals' transformational leadership, as measured by the teacher leadership competency scale, and students' academic achievement. SPSS software was used to analyze data. Purposive sampling was used and surveys with the scales were distributed to all high schools in the State of Arkansas. Results from teachers in schools that voluntarily completed online-confidential survey (n= 102 teachers) were used to answer research questions. After the analysis, the results indicated a significant relationship between teacher leadership and students' academic achievement based on the regression analysis results. Overall, transformational leadership enhanced creativity and innovation, which led to teachers' acceptance of innovation change in schools, hence improving students' academic performance and achievement. [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.]