Authentic leadership is frequently promoted as a leadership style that responds to the contemporary challenges that leaders face. The current experimental study (n = 66) tested intrapersonal change toward authentic leadership after participation in a nature‐based training program that included a stay in remote wilderness without any facilities. Authentic leadership was measured before, immediately after, and 1 year after the training program. All components of authentic leadership increased, namely self‐awareness, internalized moral behavior, balanced processing, and relational transparency, with medium to large effect sizes (d ≈ .7). Changes in general personality traits were of a lower magnitude, suggesting that change was specific to authentic leadership, rather than extending into general psychological characteristics. The findings demonstrate that a nature‐based training program can increase authentic leadership. Immersion in wilderness is possibly conducive to change in leadership style, and could be considered as a strategy for fostering leadership change.