School principals are responsible for developing a leadership culture within their buildings (Bass, 1995; Bass & Riggio, 2006). This single-case, multi-site study explored the perceptions of principals and teacher leaders on the use of transformational practices to cultivate a teacher leadership pipeline. Transformational leadership theory framed the study to examine the influence on principals' use of transformational practices to set the vision, inspire others through role model behaviors, guide the work of innovative teams and programs, and build capacity in others (Bass, 1995; Bass & Riggio, 2006). Sample selection of three high schools with five-star climate ratings provided the multiple locations for this single-case study. A total of nine participants included the principal and two teacher leaders from each of the selected sites within the same school district located in the Southeast. Data was gathered through interviews, observations of participant-led meetings, and a review of documents, and analyzed for thematic connections to the four pillars of transformational leadership theory: a) idealized influence, b) inspirational motivation, c) intellectual stimulation, and d) individualized consideration (Bass, 1995; Bass & Riggio, 2006). Findings from the study supported how principals utilized transformational leadership principal practices to foster a teacher leadership pipeline through shared vision setting, sustaining influential relationships, and shaping a leadership performance culture. Conclusions integrated recommendations for the evolution of the leadership pipeline, as follows: a) using the professional learning community model to share leadership power, b) incorporating perception surveys to monitor for a leadership culture, and c) rethinking human resource actions through the lens of teacher leaders. Implications and future suggestions for educational research centered on quantitatively exploring leadership practices, employee engagement, and teacher leadership development through the lens of the transformational leadership framework.