Purpose The purpose of this study is to investigate the effectiveness of online self-leadership training (OSLT) in promoting leaders’ self-leadership skills and recovery experiences. Design/methodology/approach A non-randomized controlled trial was conducted under two conditions: a standardized seven-week OSLT (N = 43) and a control without any intervention (N = 42). All participants (N = 85) completed standardized questionnaires measuring self-reported self-leadership skills and recovery experiences. Additionally, participants in the intervention group were assigned to invite one team member each (N = 26) to assess their leaders’ pre-post self-leadership skills and pre-post leader–member exchange. Findings Significant interaction effects of time and group and increases in the OSLT group (t1 vs t2) in self-leadership skills (cognitive and natural reward strategies) and recovery experiences (detachment and relaxation) indicated the effectiveness of OSLT training. Significant improvements in self-leadership skills and leader–member exchange were reported by team members of leaders in the OSLT group. Originality/value To the best of the authors’ knowledge, this study was the first to examine the effectiveness of OSLT for leaders in business contexts in a controlled before-after intervention design. The findings of this study revealed improvements in self-leadership skills and recovery experience because of OSLT.