Abstract.Background: Gatekeeper suicide prevention programs train staff to increase the identification and referral of suicidal individuals to the appropriate resources. Aims: We evaluated Act on FACTS: Making Educators Partners in Youth Suicide Prevention (MEP), which is an online training program designed to enhance the knowledge of suicide risk factors and warning signs as well as improve participants' attitudes and self-efficacy/confidence. Method: School personnel (N = 700) completed a survey administered before and immediately after the training to assess gains in training outcomes and to evaluate participants' satisfaction with the training. Results: Results indicated that MEP participants demonstrated significant increases in suicide knowledge, attitudes, and self-efficacy. Moreover, exploratory analyses revealed moderating effects of professional role on pre-/posttest changes in self-efficacy, but not suicide knowledge or attitudes. Specifically, guidance counselors demonstrated significantly smaller increases in self-efficacy/confidence compared with teachers and classroom aids, whereas teachers demonstrated significantly larger increases in self-efficacy/confidence compared with administrators. The majority of school personnel who completed the MEP program were satisfied with the training content and experience. Conclusion: Although the current findings are promising, more rigorous evaluations employing randomized controlled research designs are warranted to adequately determine the effectiveness of the MEP program.