Dr. Mary Libby is the deputy chief of diverse learners for the School District of Philadelphia, where she leads system-wide initiatives to advance access and excellence for the district’s most diverse student populations. Dr. Libby joined the district leadership team in January 2025 following her tenure as an assistant superintendent in a neighboring district. She previously served four years as the principal of the Chester A. Arthur School, where she galvanized a historic student-led initiative to rename the school the Marian Anderson Neighborhood Academy in honor of the civil rights icon. Under her leadership, the school achieved 8% and 13% increases in reading and math proficiency, earning a spot as one of the top ten schools globally for the T4 Education World’s Best School Prizes in the Supporting Healthy Lives category.

Prior to these executive roles, Dr. Libby spent over ten years in various instructional leadership capacities, including serving as a teacher, department chair, and professional learning specialist. Dr. Libby’s work is anchored in a deep value for diversity, a deep belief in the power of collective action, and a deep commitment to creating inclusive environments where each learner is empowered to exceed their limitless potential. A frequent speaker at local, national, and international conferences, Dr. Libby earned a doctorate in reading, writing, and literacy from the University of Pennsylvania, and holds a certificate in school management and leadership from Harvard University.