Background: School mental health literacy programs, delivered at the universal level, are key to promoting positive behavioral health for all youth. Successfully implementing these programs requires adaptation to ensure the programs are aligned with contextual demands of the schools in which they are implemented. Yet, little is known about how to adapt and implement mental health literacy programs in school settings. Purpose: This article describes the process of adapting and implementing an educator-delivered school mental health literacy program in the context of a large comparative effectiveness trial. Adaptations are organized around ecological systems theory to provide a comprehensive account of the changes that were made. Method: Examples from 11 middle schools illustrate multilevel adaptations that fostered implementation. Results: A case study details specific adaptations made at one school to improve implementation over 3 years. Dosage data portray increasing trends in implementation over time. Discussion: Findings are contextualized alongside the adaptations that were made, highlighting the importance of offering flexibility in delivery, identifying champions, and making iterative adaptations over time in response to local and societal changes. Translation to Health Education Practice: The article concludes with considerations to researchers and practitioners, including Health Educators, interested in implementing school mental health literacy programs.