Mass homelessness emerged in Canada in the wake of neoliberal policies that reduced government production of housing and other supportive measures. Efforts to reduce homelessness have occurred in three stages: 1) an emergency response in the 1990s that consisted mostly of investment in shelters, soup kitchens, and day programs, 2) the implementation of community plans to end homelessness, combined with the adoption of Housing First as a strategy that seeks to provide reliable shelter as a first step to anyone without it, followed by other remedial services, and 3) the recent development in Canada of early intervention strategies to prevent homelessness from its inception. The second stage was highly successful in dealing with the situation of chronically homeless adults, and many communities have begun to see reductions in homelessness. However effective, this approach does not break the cycle by intercepting potentially homeless individuals in their youth, which is when it begins for many people. Canada is at the beginning stages of the move towards a stronger focus on prevention, aided by a social innovation agenda to identify, design, test, and evaluate preventive interventions to determine which ones will be most strategically effective, setting the stage for implementation and going to scale.