Efforts to improve retention in science, technology, engineering, and mathematics (STEM) majors frequently utilize peer mentors and/or leaders. At Northern Kentucky University, the STEM Ambassador (SA) program involves students in the creation of a STEM community through multifaceted roles as mentors, peer-learning facilitators, and social organizers. The program utilizes best practices in organizational leadership and leadership development to maximize the effectiveness of the SAs. The program has resulted in positive perceptions of the SAs, increased retention of STEM students that participate in the SAled activities, and a well-nurtured, professionally developed set of students that serve the STEM community.