Mindfulness training has emerged as a potential intervention for reducing teacher stress and improving student outcomes. However, few studies have focused on teachers implementing mindfulness-based interventions (MBIs) for themselves and their students, or examined the fidelity, feasibility, and social validity of these MBIs in classrooms. Community-based participatory research (CBPR) and Making Optimal Decisions for Intervention Flexibility during Implementation could address current limitations by fostering equitable partnerships between researchers and teachers. The first aim of the qualitative study will be to collaborate with twelve elementary teachers to develop and provide input to the MBI through the CBPR and MODIFI framework. Cultural adaptations to the MBI will be included to explore social validity.  The second aim of the study will be to use a single-case multiple baseline design across at least eight of the teachers from the previous study to evaluate the MBI teachers created consisting of self-practice and classroom-based implementation. The effects on teacher stress and student prosocial behavior will be assessed, along with implementation fidelity and sustainability.