Leadership development is a multi-billion-dollar industry with a strong focus on learning through experiences, yet most experiential leadership development efforts typically center on work-based experiences and not personal life experiences. This study delves into the relationships among significant life experiences, leader identity, and adult development in the workplace. It aims to bridge a critical gap in leadership development literature by offering deeper insights into how life experiences contribute to the development of leader identity and adult development. The methodology involved a qualitative analysis of the experiences of 27 diverse, seasoned leaders across various industries, emphasizing a holistic approach that integrates personal life experiences with professional leadership growth. The study's key findings are pivotal in understanding the influence of life beyond work on professional leadership. First, non-work significant life experiences are found to relate to leader identity and adult development in the workplace. Second, reflection and sensemaking are instrumental in shaping how both work and non-work experiences influence leader identity and adult development. Third, various stages of adult development influence the development of a leader's identity through their significant life experiences. Fourth, significant life experiences are shown to promote leader development by enhancing self-awareness and perspective-taking capacity. Additionally, many leaders felt they were able to develop positively as a result of a negative experience, and their interpretation of significant life experiences may change over time. Lastly, the interview process itself may act as a catalyst for development. Together, these findings offer a transformative perspective on leader development, emphasizing the integration of personal life into professional growth. The implications of these findings are substantial for leadership development practices because they provide insight as to how sensemaking and reflection of significant life experiences can influence leadership development. By acknowledging the significant role that personal life experiences play in shaping leadership journeys, organizations can design more effective and resonant leadership development programs that provide the time, space, and structure to support leader reflection and sensemaking activities. These programs can foster more authentic and effective leaders, better equipped to meet the challenges of the modern workplace. This research thus contributes substantively to the field of leadership development, offering insights that extend beyond theoretical abstraction to practical application. [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.]