This article describes the design and implementation of Gavi’s Zero-Dose Learning Hub initiative, a multi-country effort to strengthen evidence generation and use to better identify and reach zero-dose (ZD) children and missed communities. Operating across Bangladesh, Mali, Nigeria, and Uganda, ZDLH combines rapid assessments, implementation research, improved monitoring, and country-specific learning agendas to generate actionable insights within national health systems. The initiative also emphasizes knowledge translation and cross-country synthesis to ensure that evidence informs programmatic decision-making at subnational, national, and global levels. As a structured learning model, ZDLH provides a framework for embedding continuous learning and evidence use to improve immunization coverage and primary health care access.