We examined the relationship between high school and collegiate organizational involvement and their differential and collective effects on the development of leader self-efficacy, motivation to lead and leadership skill. Our goal was to better understand how the student leader development process unfolds at different points in time over young adulthood. The study investigated members of registered student organizations (n=757) during the Fall 2016 semester. Results of the study indicated strong developmental relationships between past high school involvement, current collegiate involvement and leader capacity change. Positional leadership and students' priority placed on their involvement during high school were predictive of leader skill and self-efficacy, while in college, only mental and physical engagement in organizations predicted leader development.