Teacher retention, commitment, and organizational effectiveness represent intersecting policy challenges facing Zambia’s educational systems. This mixed-methods study, drawing on Authentic Leadership Theory and Social Exchange Theory, examines authentic principal leadership as a mechanism for building teacher affective commitment and enhancing school organizational effectiveness. Quantitative data from 402 teachers across five districts were analyzed using Structural Equation Modelling; qualitative data from 20 Headteachers were analyzed thematically. The SEM demonstrated that authentic leadership exerts an exceptionally strong effect on affective commitment (β = 0.963, p < .001) and, through this commitment, significantly drives organizational effectiveness (indirect β = 0.364; 95% CI [0.285, 0.448]), accounting for 46% of the total leadership-effectiveness relationship. Contrary to prevailing policy assumptions grounded in Herzberg and Locke, job satisfaction did not independently predict organizational effectiveness (β = 0.009, p = .825) when modelled alongside authentic leadership and affective commitment. Qualitative findings revealed four barriers to authentic leadership: cultural paternalism rooted in Lozi leadership traditions, resource constraints, systemic policy incoherence, and a mis-specified accountability framework that prioritises examination results over relational conditions. The paper proposes the CARE Policy Framework (Culturally Adaptive, Relationally Authentic, Effectiveness-Broadened) for principal leadership development and school accountability reform in Zambia.