In many parts of the world early childhood services are disconnected in ways that reduce their effectiveness in supporting family life, healthy child development, and the transition to school. Furthermore, access to these services is often limited, particularly for marginalized families. There is increasing policy interest around the world in building early childhood service systems that are universal and integrated, as a way of strengthening the effectiveness and equity of early childhood services. Although there is a growing push to unify child care and education in a universal system, both in Canada and elsewhere, a fully integrated system would bring together additional services for family support, health and community programs. The Toronto First Duty demonstration project was designed to test the feasibility and effects of a universal model for integrating child care, kindergarten, family support and other services in school-based community hubs. The intent of the project partners- a charitable foundation, municipal government, and school board- was to mobilize knowledge to improve early childhood programs and policy at both the local and provincial levels. A university-based research team has worked over the last decade to evaluate the implementation process and outcomes of the project, and has contributed to the knowledge mobilization for practice and policy change. The research found positive evidence on the feasibility of implementing the model, as well as evidence about the processes that work through program and family pathways to enhance child development and parenting. Findings from the project have helped to move provincial policy in Ontario and elsewhere in Canada. Although fixed models may not apply to new contexts, some of the evidence-informed design principles from this project converge with findings from other jurisdictions and have broad implications for policies promoting universal, integrated service systems for early childhood.