Youth Mental Health First Aid (YMHFA) trains individuals who regularly interact with youth to identify youth experiencing mental health challenges. Several studies demonstrate positive training impacts, but few assess whether the training equally impacts participants of different demographic and professional backgrounds or those who participate in different training modalities. Using a pre-post follow-up design with a comparison group, this study examined changes in participants confidence in their ability to recognize and support youth mental health needs 1 to 2 months after training. Data were collected over two years (2021-2023) from training participants (n = 480) and comparable non-participants (n = 51). The authors examined whether changes in confidence varied by participant race/ethnicity, professional role in the education or mental health fields, and training modality (online versus hybrid). Training participants confidence in supporting youth mental health increased significantly compared to non-participants. Although the training was effective for all participants, those with less mental health experience benefited more, consistent with previous research. While both in-person and hybrid training were effective, in-person training participants reported slightly higher confidence scores than virtual at follow-up. Study findings suggest that educational and social service organizations should offer this training to their staff and community members who interact with youth, prioritizing participants with less prior mental health training and delivering training through an in-person training modality when possible. However, additional research is needed to explore how aspects of in-person training, such as trainer characteristics and group dynamics, impact outcomes.