PurposeDespite a fast-growing interest in leadership development programs, there is limited research on the impacts of leadership development and a narrow focus on professional competencies as outcomes. The authors’ aim was to test whether authentic leadership development (ALD), an identity-based leadership development approach, is associated with positive changes in leaders' psychological well-being.Design/methodology/approachIn a large sample of leaders (N = 532) from five different ALD programs, the authors conducted a pre-registered outcome-wide analysis and tested within-person changes in key indicators of psychological well-being and explored individual differences moderating these changes.FindingsResults showed significant increases in self-concept clarity, sense of purpose in life and personal growth about two to three weeks after the programs ended. Changes in stress and health were not consistent. These changes did not differ across socio-demographic status (gender, age), work-related factors (leadership, industry and tenure) and most personality factors (extraversion, agreeableness, openness to experience). Those with high emotional variability experienced greater improvements in some outcomes of well-being while individuals with higher income and conscientiousness (who had high baseline self-concept clarity) experienced smaller improvements. Longer follow-up assessments were associated with smaller changes.Originality/valueAs one of the most comprehensive assessments of ALD outcomes to date, this study shows the potential of ALD for improving outcomes beyond leadership skills, the well-being of leaders, highlighting the return on value in leadership development and pointing to learning and development as a workplace well-being intervention.