Schools have an important role to play in combatting suicide, a significant public health problem that disproportionately affects adolescents and young adults. Schools can work to reduce youth suicidality by adopting policies that align with best practice recommendations pertaining to suicide prevention, intervention, and postvention. This study examined the impact of a one-day training, the Creating Suicide Safety in Schools (CSSS) workshop, on the readiness of school personnel to improve their schools’ suicide-related policies and procedures. Participants (N = 562) consisted predominantly of school-based mental health professionals working in communities of low or mixed socioeconomic status in New York State. Survey data were collected according to a one-group pre-test—post-test design with a 3-month follow-up. Workshop participants demonstrated improvements from pre-test to post-test in their attitudes about the importance of school-based suicide prevention, knowledge of best practices, perceptions of administrative support, and feelings of empowerment to work collaboratively to enhance their schools’ suicide safety. At follow-up, participants reported barriers to implementing changes, most commonly in the form of insufficient time and stigma surrounding the topic of suicide. The results of this study provide preliminary evidence for the effectiveness of the CSSS workshop as a promising method for improving schools’ suicide safety, yet additional research using randomized controlled trials needs to be conducted.