The prevalence and severity of adolescent mental health concerns is clear. Half of youth experience a trauma/adverse event, thus significantly increasing their risk of developing mental illness. Further, suicide recently became the second leading cause of death among young people. Unfortunately, most youth do not get the mental health services they need. Schools, however, are the most likely place to provide formal or informal mental health care. Classroom educators, in particular, are most likely to be the one to refer/recommend students to formal school mental health services and they also provide informal mental health help. Despite their key role, they often feel underprepared to recognize concerning symptoms in youth and to support school mental health efforts. This mixed-methods study explored the impact of training 106 City Year AmeriCorps members in Dade County (Miami, Florida) using the Youth Mental Health First Aid (YMHFA) program. Quantitative data were collected at three points (pre, post, and two months after training) to examine whether YMHFA training equipped corps members with tools to support students’ mental health. Overall, training was associated with short-term improvements in mental health literacy, confidence and intentions to engage in providing mental health first aid behaviors, and knowledge of school based mental health providers. Notably, participants self-reported greater engagement in mental health helping behaviors in the two months after training than in the two months before training. No improvement in mental health stigma was observed, and some short-term improvements (i.e., mental health literacy, intentions to help) were not sustained at follow-up. Qualitative data generally supported quantitative findings and suggested that the YMHFA program is well-suited for classroom educators. However, the program has room to grow in ensuring it helps educators support culturally and linguistically diverse students’ mental health.