Recognizing that children's learning outcomes generally remain low, in its recent 2017--2021 Education and Skills Sector Plan (ESSP) the Government of Zambia prioritized improving learning outcomes through strategies that addressed gaps in education system quality, access, equity and efficiency. What resources and contextual factors are associated with school performance in Zambia? By merging and analyzing existing administrative datasets in Zambia, this report helps to identify positive deviant schools -- those that outperform other schools despite sharing similar contexts and resources. Data Must Speak -- a global initiative implemented since 2014 -- aims to address the evidence gaps to mitigate the learning crisis using existing data. The DMS Positive Deviance research is co-created and co-implemented with Ministries of Education and key partners. DMS research relies on mixed methods and innovative approaches (i.e., positive deviance approach, behavioural sciences, implementation research and scaling science) to generate knowledge and practical lessons about 'what works', 'why' and 'how' to scale grassroots solutions for national policymakers and the broader international community of education stakeholders. DMS research is currently implemented in 14 countries: Brazil, Burkina Faso, Chad, Cote d'Ivoire, Ethiopia, Ghana, the Lao People's Democratic Republic, Madagascar, Mali, Nepal, Niger, the United Republic of Tanzania, Togo and Zambia. [The Data Must Speak (DMS) positive deviance research in Zambia is a collaborative effort made possible by the commitment of the Ministry of Education (MoE) Zambia, UNICEF Zambia, UNICEF Innocenti -- Global Office of Research and Foresight, and key partners from the Zambian education sector.]