The purpose of this qualitative descriptive study was to describe the leadership styles of Catholic school principals in California who lead professional learning communities. It is not known how Catholic elementary school principals describe their leadership styles when leading professional learning communities. The overarching research question was: How do Catholic elementary school principals describe their leadership style? (laissez faire, transactional, or transformational). The theoretical foundation for this study was the full range leadership model. The sample for this study included elementary Catholic school principals in California who had been at the school site for at least a year and had the characteristics for a professional learning community. Data collection for this qualitative descriptive study included a Self-Administered Mixed Questionnaire comprised of open and close ended questions and the Multi-Factor Leadership Questionnaire. In addition, this study utilized semi-structured interviews. Data analysis included descriptive summaries and thematic analysis. The findings from this study yielded eight themes. The results indicated that the Catholic school principals were more transformational in their approach when leading professional learning communities at their school sites. When leading professional learning communities, the Catholic school principals energize and inspire their staff; are entrenched in community; are visionaries with mindset and actions; are steadfast in expectations and firm in beliefs; share responsibilities; build capacity; are considerate of others; and create avenues for communication with their staff. [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.bibliotheek.ehb.be/en-US/products/dissertations/individuals.shtml.]