Thesis advisor: Raquel Muniz / There is an abundance of research that both supports teachers’ developing the social and emotional competencies (SEC) of students and acknowledges that doing so positively impacts students’ academic and life success, as well as improving general well-being. As of 2020, Massachusetts required teachers to provide social emotional learning (SEL) opportunities for students, but district and school leaders have done little to develop teachers' own SEC.  Yet, the literature shows that teachers’ SEC matter, both to the successful implementation of SEL programs in classrooms and to teachers’ own ability to manage their emotions and handle stress. Teaching is stressful and high emotional stress can lower resilience and impact job performance. This qualitative case study examined the practices of school-based leaders in one Massachusetts public school district to determine which leadership practices developed and supported the resilience and well-being of school-based staff and how those practices promoted SEL opportunities for staff. Data was gathered from leaders and school-based staff through semi-structured interviews, questionnaires, and document review. Findings revealed that leaders developed and supported staff resilience and well-being when they provided opportunities for collaboration, recognized and provided feedback to staff, included staff in decisions related to their work, and supported work-life balance and self-care. Engaging in these leadership practices allowed leaders to promote SEL opportunities for staff and often modeled SEC for staff. / Thesis (EdD) — Boston College, 2020. / Submitted to: Boston College. Lynch School of Education. / Discipline: Educational Leadership and Higher Education.