Objective: The current study evaluated the long-term effectiveness of a peer delivered suicide prevention gatekeeper training program for college students. Participants: 1,345 undergraduate students (M[subscript age] = 20.24, SD = 3.27; 89.6% White) received the peer led training during a single class-period. Method: Participants completed pre- post- and 3-month follow-up surveys assessing knowledge, perceived intervention skills, willingness to intervene, and self-efficacy. Engagement in gatekeeper behaviors were assessed at follow-up. Two open-ended questions provided data for qualitative analysis. Results: Both quantitative and qualitative data indicated that participants showed substantial increases in all outcomes from pre- to post-training, and these gains were maintained at follow-up. Participants reported engaging in gatekeeper intervention behaviors at follow-up and qualitative results provide evidence this was due to the training. Conclusion: Peer led suicide prevention gatekeeper training is feasible, appears to be effective, and can enhance campus' capacity to provide sustainable suicide prevention programming on campus.