This qualitative, phenomenological study examined undergraduate peer mentors' perceptions of the mentoring roles and their perceived student learning through their mentoring experiences. The participants' experiences were connected to the sociocultural theory of learning and self-determination theory. The study revealed four themes from peer mentors' perceived roles, including a strong desire to help, an active role in guiding mentees' growth, the challenges peer mentors face, and psychosocial support to mentees. Throughout their mentoring process, peer mentors also recognized their own learning in the areas of communication, diversity appreciation, relationship building, professionalism, leadership, and self-awareness. These perceived learning outcomes were intricately intertwined, with no absolute boundaries between them. Despite some challenges peer mentors experienced, they reported an overall positive impact peer mentoring had on their own college experiences. The results of this study have implications for current and future peer mentors, administrators, and higher education institutions. By contributing to the existing body of research on the experiences and perceived learning of undergraduate peer mentors, this study provides valuable insights that can enhance peer mentor training and practice. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]