This paper examines country and region-specific determinants of childhood undernutrition in the Sahel which, if integrated into nutrition action, could accelerate progress in the region. Additionally, this research includes the analysis of determinants that have not previously been examined comprehensively or included in nutrition action. The authors assessed the most recent nationally representative cross-sectional Demographic and Health Survey data, between 2010 and 2018, from five Sahel countries. Multilevel logistic and linear regression models were used to assess the association between childhood undernutrition and child, parental, and household level factors. Our analytical sample included just under 37,000 children under five years old.