This study aims to investigate how university students' self-leadership affects institutional commitment by using their self-efficacy as a mediating factor. To gather data, a web-based survey was given to students at four-year public and private universities in Seoul. The final sample size is 347, and the research findings are as follows: First, students' self-leadership positively affects their institutional commitment. Multiple regressions showed that behavior-focused strategies and natural reward strategies have a direct and positive effect on institutional commitment. Second, students' self-leadership positively affects their self-efficacy. Third, students' self-efficacy positively affects their institutional commitment. Last, students' self-efficacy mediates the relationship between self- leadership and institutional commitment. A mediator analysis showed that through self-efficacy as a mediator, all self-leadership strategies affect institutional commitment. This is the first study to examine relationships between self- leadership, self-efficacy, and institutional commitment among undergraduate students. This research has implications for the importance of increasing students' commitment to universities, self-leadership, and self-efficacy. It also gives researchers and practitioners helpful information about setting up self- leadership and self-efficacy programs to help students become more committed to their institutions and become successful and versatile self-leaders.