School mental health programs are an important component of the national response to the current student mental health crisis. However, evidence-based programs often face numerous barriers to their selection, scale-up, and sustainability in real-world settings. In this study, we interviewed 15 educational stakeholders to examine what influences their selection of school-based mental health programs. Interviews focused on factors influencing the selection and sustainability of mental health programs in schools. We coded transcribed interview data using a hybrid, iterative process, and generated themes from these codes. We identified five categories of themes related to key decision-making criteria: program fit with student and school needs, evidence of program effectiveness, stakeholder buy-in, logistical considerations for staff delivering programs, and cost and resource requirements. Findings have implications for researchers who wish to improve dissemination strategies for school-based mental health prevention programs and for policymakers who wish to shape funding priorities to support greater diversity in program availability. Findings are also useful to practitioners who may use these insights to reflect on their own program selection practices or may see their own experiences reflected and normalized through the lens of the key themes presented here.